Magnesium is one of the most commonly used supplements in horses, which when used appropriately, can be significantly beneficial. Yet often little consideration is given to important specifics around the use of this mineral. These generally overlooked nuances can help to determine how effective the magnesium is and if it is actually helpful or harmful to give your horse.

Magnesium plays many vital roles in the body. It is needed for over 300 enzymatic processes. From helping ‘wired’, reactive or anxious horses to reducing inflammation, supporting fertility, promoting bone health, metabolic function, and insulin regulation, magnesium has a wide range of applications.

Because magnesium is a naturally occurring nutrient, it is frequently assumed to be completely safe and free from side effects. Yet in reality, it isn’t quite this simple. Like many other supplements and nutrients, there are many factors which determine the safety and effectiveness of magnesium: how and what it is used for, the quantity of magnesium a horse is given, the duration of supplementation, the form of magnesium used, a horse’s overall diet and intake of other specific nutrients, exercise and activity levels, breed, sweat rate, any health conditions a horse may have, the state of its gastrointestinal health and any medications a horse is on. 

If you’re already supplementing or considering using magnesium for your horse, here are some key things worth considering.

Not all magnesiums are created equal

Magnesium comes in a variety of forms, depending on what it’s bound to. This refers to the chemical structure of the magnesium, not just whether it is in liquid or powdered form. The most commonly used forms of magnesium (which also tend to be the cheapest forms of magnesium) in equine supplements include:

• Magnesium oxide
• Magnesium chloride
• Magnesium sulphate

Each of these forms differs in terms of absorption, bioavailability, and how they interact with the digestive system. Yet they are generally not the most clinically effective forms of magnesium to use.

This matters more than many people realise.

Magnesium can irritate the gut

Some forms of magnesium, particularly at higher doses can irritate the digestive tract.

Clinically, this may present in our horses as:

• loose and/or more frequent manure
• gassiness/excessive passing of wind
• changes in gut comfort and/or signs of mild colic
• worsening of existing digestive sensitivity

This is often dismissed or overlooked, especially if magnesium is being used for behavioural reasons.

Over-supplementation can disrupt the gut microbiome

High doses, poorly absorbed forms of magnesium or long-term over-supplementation may contribute to gut dysbiosis (an imbalance in gut bacteria). This can have wider consequences, including:

Magnesium can help to promote a healthy gut microbiome and reduce gastrointestinal-associated inflammation, but more is not always better.

• negative impacts on immune function
• altered nervous system function
• changes in neurotransmitter production and function

Our horses’ digestive systems can play a significant role in their behaviour, anxiety levels and learning capacity, thanks to the role of the gut-brain axis. Ironically, this means that excessive magnesium use may actually make some horses more reactive or sensitive, not less.

Magnesium can interfere with other essential nutrients, causing relative nutrient deficiencies

Magnesium doesn’t work in isolation. It interacts closely with other minerals including:

• calcium
• phosphorus
• zinc

Excess magnesium can interfere with the absorption and utilisation of these nutrients, which are critical for:

• bone strength and development
• proper neuromuscular function
• healthy immune function
• healthy nervous system function
• reducing oxidation and inflammation 
• muscle, tendon and ligament health

Calcium and zinc in particular, play key roles in the synthesis and function of neurotransmitters such as:

• Dopamine
• Serotonin
• GABA

Imbalances in these neurotransmitters can directly influence behaviour, sensitivity, pain perception, reactivity, learning ability and response to training.

Magnesium and behaviour: not always a simple fix

Magnesium is often used to help calm or relax our horses, and in some cases, when used appropriately it can be most beneficial. When magnesium doesn’t help to address the underlying cause(s) of anxious or excitable behaviour however, the effects of supplementation will be minimal.

The effectiveness of magnesium supplementation will also be minimal and may compound behavioural issues if the delicate balances of other minerals are disrupted, magnesium is overused, poorly bioavailable forms of magnesium are employed, or the gut microbiome is negatively impacted. In these cases behavioural issues may actually worsen rather than improve.

It is important to remember that many things can contribute to adverse behaviour in our horses, and in the vast majority of cases, there are multiple causes at any one time, not just one single factor. Whilst diet, nutrient deficiencies and gut microbiome all play an important part, it would be remiss to overlooked issues such as pain, learned conditioning, side effects of other medications used (if applicable) and other underlying health issues. Supplemental magnesium will be of very limited benefit if the issues causing a horse’s poor behaviour are not properly addressed.

This is why a blanket approach to supplement with magnesium doesn’t always deliver consistent results.

Where magnesium can be highly beneficial

When used appropriately, magnesium can be valuable, particularly in horses with:

Metabolic Challenges

Magnesium plays a role in regulating blood glucose and insulin levels. It can be especially supportive in horses with:

• insulin resistance (IR) or insulin dysregulation (ID)
• equine metabolic syndrome (EMS)
• laminitis or at risk of laminitis

Increased Physical Demand

Horses lose magnesium through sweat, and in the case of broodmares, through their milk. Requirements may increase in:

• horses in intense workloads
• hot and/or humid climates
• lactating mares
• during travel

In these cases, intake may increase in the range of 1.5 to 2 times maintenance levels.

Diet still matters: natural sources of magnesium

Like many minerals, magnesium naturally occurs in feeds commonly given to our horses. Lucerne (alfalfa) hay is a useful natural source of magnesium. Fortified concentrate and balancer feeds have varying levels of magnesium.

However, it is not always quite as simple as relying on feed alone (or even, relying on nutritional information on a feed bag or product label).

Feeds or supplements which contain high levels of calcium (such as lucerne/alfalfa) can inhibit magnesium absorption to some degree. This highlights the importance of looking at the whole diet, not just individual nutrients or feed components, nor relying on feed programs or calculators alone.

Medications can change magnesium requirements

Many commonly used medications in horses can alter magnesium absorption, metabolism, or excretion, meaning their requirements may shift.

These include:

• corticosteroids
• proton pump inhibitors (the include the most commonly used ulcer medications which contain omeprazole)
• antibiotics
• non-steroidal anti-inflammatory drugs (NSAIDs)
• antihistamines
• clenbuterol  (β2-agonists, which are often sold under names such as Claire Gel, Broncopulmin, Airway Gel, Ventipulmin, Equipulmin, etc).

If your horse is on medication, magnesium supplementation should always be considered more carefully. Dose, form, timing and duration of magnesium supplementation is crucial to take into account.

In summary: use magnesium strategically, not automatically

Magnesium is a powerful and valuable tool in equine nutrition and medicine, but it’s not without its limitations.

Used well, it can support:

• metabolic health
• muscle function
• nervous system balance and in turn, behaviour 
• skeletal health
• fertility
• gastrointestinal (‘gut’) health

Used poorly, it can:

• disrupt gut health
• create mineral imbalances and relative nutrient deficiencies
• contribute to ongoing behavioural issues
• interfere with normal bone development and health

The key is not just whether your horse is supplemented with magnesium, but what their actual requirements for it are. The form of magnesium used to supplement, the reasons to supplement it, the duration of supplementation, factors which increase requirements or interfere with magnesium absorption and metabolism should all be taken into consideration.

Take home message

Good equine nutrition is never about using a single supplement in isolation. Assessing the unique needs of the individual horse in front of you is crucial.

Before supplementing magnesium, it’s always worth asking:

• does my horse actually need it? And if so, how much?
• is the diet balanced overall? And what role would supplemental magnesium potentially play in this?
• could there be deeper underlying causes contributing to the reasons which are prompting me to supplement magnesium?

The safest, most effective and sustainable results come from a thoughtful, tailored approach.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Equine asthma is a condition that can affect horses of all abilities, but is most frequently diagnosed in performance horses and racehorses, and is a common cause of poor performance. The term ‘equine asthma’ covers a broad range of inflammatory conditions of the lower airways, which can vary in their presentation and severity. Conditions that were previously referred to as ‘recurrent airway obstruction’, ‘heaves’, ‘inflammatory airway disease’, ‘chronic obstructive pulmonary disease’, and ‘summer pasture associated asthma’ are now all known as ‘equine asthma’.

When a horse has been diagnosed with, or is suspected of suffering from asthma, it is natural for us to want to provide them with relief. From a pharmaceutical standpoint, that can often mean the use of corticosteroids and, in many cases, clenbuterol (often sold under names such as Claire Gel, Broncopulmin, Airway Gel, Ventipulmin, Equipulmin, etc). While use of these medications may help relieve some clinical signs of asthma, they do not address the underlying causes of the condition and may also come with unintended health consequences. Unfortunately, these side effects are often overlooked, or simply not discussed.

Whilst clenbuterol may provide some initial relief in equine asthma, the use of this drug can contribute to a vicious cycle, potentially perpetuating the condition.

Clenbuterol has been demonstrated to deplete the amino acid taurine. Taurine plays a significant protective role in lung health by exerting powerful anti-inflammatory, antioxidant, and membrane-stabilising effects. It also helps to inhibit allergic responses, which can play a role in many cases of equine asthma. Reduced taurine levels may increase the severity of equine asthma and the likelihood of lung tissue damage as a result of ongoing airway changes. Taurine is also needed to promote healthy gut integrity and microflora: gut health is increasingly recognised as an important factor in respiratory conditions such as asthma.

Clenbuterol decreases levels of potassium and magnesium in the body—two key nutrients known to support respiratory health and reduce the severity of asthma. Potassium is essential for controlling airway smooth muscle tone and supporting respiratory muscle function.  Low potassium can increase airway reactivity and hamper breathing, further exacerbating clinical signs of asthma. Depleted potassium levels can also lead to cramping in susceptible horses. Magnesium acts as a bronchodilator (helping the airways relax) and helps reduce airway hyperactivity, spasms, and inflammation.

Long-term use of clenbuterol may also have negative impacts on immune function, further contributing to a self-perpetuating cycle of equine asthma.

An often overlooked side effect of clenbuterol is the influence it may have on temperament and behaviour in our horses. Clenbuterol belongs to a class of drugs known as beta-2 adrenoceptor agonists, which work by mimicking the effects of epinephrine (adrenaline) in the body. This results in a stimulating effect, which may lead to changes in behaviour, including increased excitability, reactivity or nervousness in some horses.

Helping a horse at risk of, or diagnosed with asthma, starts with good management practices. Identifying and appropriately addressing the factors that contribute to the underlying pathophysiology of equine asthma, meeting the individual horse’s nutritional requirements (which often differ from basic nutrient requirements due to medication use), and the judicious use of suitable herbal medicines can significantly support respiratory health, allowing a horse to remain healthy and perform at its best. There is much that can be done for the horse diagnosed with asthma, using approaches that not only support airway health and performance, but also promote overall wellbeing. If your horse has been diagnosed with asthma, or you suspect respiratory issues may be affecting performance or comfort, a tailored approach can make a significant difference. Get in touch with Optim Equine to discuss a personalised plan to your support your horse’s health and performance.

At Optim Equine, we regularly work with horses affected by respiratory conditions…

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Depending on the herb (or combination of herbs used) and their application, they can help to:

• reduce inflammation
• modulate immune function
• aid healing and tissue repair
• assist recovery from infections
• prevent and/or manage equine asthma
• soothe the gut lining and promote healing of both gastric and colonic ulcers
• reduce colic 
• support digestion
• assist fertility
• help regulate hormone levels
• calm nervous horses
• provide gentle pain relief
• promote healthy hoof growth and integrity
• help to reduce the severity of osteoarthritis and maintain joint health
• Aid in blood glucose control and assist in the treatment of insulin resistance, equine metabolic syndrome and laminitis

Whilst herbal medicines are incredibly versatile, they’re not magic. And they can’t replace a poorly balanced diet….

One of the biggest misconceptions I see is that herbs can fully meet a horse’s nutritional needs or correct nutritional deficiencies on their own. 

This is simply not true. 

The vast majority of herbs (with few exceptions) do not provide sufficient quantities of key minerals and vitamins our horses need for optimal health and functioning.

Take the calcium rich herb nettle (Urtica diocia) for example….

100 g dried nettle leaf (~4–5 cups) provides approximately 300–500 mg calcium.

For a 500 kg (1100 pound) horse, calcium requirements typically fall in the range of 20–40 g/day (depending on life stage, workload, and physiological status).

This means:

• 100 g nettle provides roughly 0.3–0.5 g calcium
• This equates to approximately 1/40 to 1/133 of daily calcium requirements

To meet calcium needs via nettle alone would require:

• 4–5 cups × 40–133 = ~160–665 cups per day

This is neither practical nor appropriate.

Whilst strategically employed herbal medicines can help to restore optimal gastrointestinal health and function in our horses (including digestion, absorption and metabolism)- which in turn, can aid in better nutritional status, herbs in and of themselves don’t provide enough levels of nutrients our horses needs to meet daily nutrient requirements.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

It seems almost impossible to read news reports and social media posts these days without coming across someone telling you how important it is to look after your microbiome. From managing our mood and our weight, to reducing the risks of any number of diseases, someone, somewhere, will make a link to the billions of bacteria living in you, or on you.

But a recent study, published in the open-access journal Nature Scientific Reports, made a new and extraordinary connection: a foal’s internal hitchhikers may affect how fast he runs. And not just that – they can predispose to, or protect from, a range of conditions that might even prevent him from racing at all.

The paper followed 52 foals, born between February and May 2018, from five Thoroughbred stud farms in the UK. These foals were followed as they entered training (dispersed between 29 different training yards) and through to the end of their 3-year-old season.

In the earliest part of the study, faecal samples were obtained from each individual on day 2 postpartum and at regular intervals up until one year of age. These samples were then analysed and the number, variability, and different types of bacteria in the samples were assessed and recorded. The study was prompted by increasing evidence that not only are there a range of non-communicable diseases in humans affected by the bacteria within the intestines, but also that babies with differing birth and early-life circumstances may be predisposed to certain conditions, because of differences in their microbiome. 

The clinical and racing histories of the foals were then compared to the results of the microbiological evaluations. 

The results were striking: the gut bacterial community in the first months of life could predict the risks of specific diseases and athletic performance in later life. Foals with lower diversity (i.e. fewer different species of bacteria in their samples) at one-month-old had a significantly increased risk of respiratory disease in later life. A higher diversity was associated with a decreased risk of orthopaedic disease. And, when athletic performance was assessed — judged by comparing official ratings, number of starts/wins/places, and prize money earned — positive effects were again seen in foals with a greater diversity of bacteria at one-month-old and could even be linked to the relative abundance of specific bacterial families.

Foals are born without a functioning microbiome and must acquire all of their gut bacteria from their dam and their environment. This early phase of development, where foals are born with an immune system that is yet to encounter external challenges, is sometimes referred to as a ‘critical window’ — essentially a period when the gut microbial community imprints immunity and future health outcomes onto a blank canvas. There is now a great deal of interest in humans as to how this might be contributing to a variety of diseases: from obesity, diabetes and allergies, to diseases of the circulatory system, bones and neurodevelopment disorders such as autism. 

This particular study did not examine the gut microbial profile of the mares delivering and rearing the foals. But the authors point out that the gut bacterial profile of human mothers is known to be a primary driver of gut colonisation in human infants. Indeed, in human medicine, there is increasing engagement of methods to optimise this ‘handover period’ in neonates. There is limited evidence for how feeding mares may influence foals in this early phase. But a recent study, that fed two groups of mares on the same stud farm separate and distinct rations, demonstrated a stark difference in failure of passive transfer — assessed by levels of IgG in the foals’ blood within twenty-four hours of birth — between the two sets. Other researchers have confirmed that the microbial population of foals varies between stud farms, most likely due to differences in management styles. Numerous studies in other species have demonstrated links between maternal nutrition and various measures of colostrum quality, and there is evidence that a pro-inflammatory profile is seen in colostrum produced by obese mares, along with reduced medium-chain saturated fatty acid levels (important as an energy source and in the development of gut microbiota and immunity).

So, what if the balance could be tipped back in favour of the newborn foal, simply by adjusting how the mare is fed? And what if this could also affect the vigour of our young athletes? The developmental origin of health and disease (DOHaD) — first advocated by David Barker in the early 1990s — seeks to understand how exposure to environmental factors during periods of high plasticity in the early stages of life (including the gestational period) influences the program for development and disease risk in the progeny, that extends well into adult life.

Before the middle of the twentieth century, the foetus was believed to be immune from the effects of the maternal environment. It is now understood that in laboratory animals and humans, which is where of course almost all of this research has been done, numerous external factors influence the health and development of the foetus before birth. Historically, the focus has been on those causing adverse effects, such as polycyclic aromatic hydrocarbons — found in vehicle exhaust fumes and cigarette smoke — alcohol, and certain notorious pharmaceuticals. Epidemiogical studies began to link certain aspects of development, some not immediately obvious at birth, with environmental factors that had not been appreciated earlier and may be influenced by microbiome effects. For example, having “furry pets” at home impacts meconium bacterial diversity, and children reared with domestic animals from infancy have reduced prevalence of allergic-related diseases; maternal consumption of artificial sweeteners produces profound metabolic changes and microbiome changes in mouse pups (with profiles similar to those seen in human obesity). ‘Barker’s theory’ on the foetal origins of adult disease considered three characteristics: latency, where the effects may not be apparent until much later in life; persistency, in which conditions affecting the foetus continue; and genetic programming, where specific genes are switched on due to the prenatal environment. Brief windows at the very start of development, when a small number of cells are dividing rapidly and vulnerable to a range of influences, drive the development program of the entire individual, all the way through to adulthood.

Much of the work on the transferability of a healthy microbial population from one individual to another was prompted by early observations, reported in 1958, that patients affected by a particularly unpleasant and intractable cause of severe diarrhoea showed drastic improvements following a novel treatment. Clostridioides difficile is an anaerobic bacteria (it thrives in low-oxygen environments), commonly found in the intestinal tract of normal people. It doesn’t cause any issues until it proliferates uncontrollably, and the commonest reason for this is when the other bacteria in the intestine ecosystem are knocked out, usually by the patient receiving antibiotics for another problem. ‘C. diff’ is the commonest cause of antibiotic-associated diarrhoea, and it is notoriously difficult to treat in some cases — it only responds to a select group of antibiotics, many cases remain refractory, and it has a fatality rate of up to 40%. Back in the 1950s, the doctors were utilising a therapy that had been written about in the fourth century: transplanting gut bacteria from a healthy individual into the affected patient. And they did so by taking faeces from those healthy volunteers and delivering it via an enema (the very earliest records describe it being given as a ‘soup’).

Faecal microbiota transplantation (FMT) is now used in cases of C. diff that do not respond to first-line treatments and is well established for this, with impressive success rates of 80-90%. It works because it restores the normal balance of gut microbes, which prevents the Clostridia from maintaining a hold on the intestinal environment and, basically, out-competes them for the resources available. But as well as this, restoring the regular bacteria found in a healthy gut revitalises the relationship between the host —  us, or the animal — and the trillions of single cell organisms we live with.

Estimates of the numbers of bacteria within the body vary, but it’s safe to say it’s in the tens of trillions. It’s also safe to say that in most people the bacteria outnumber the human cells, in some cases by an order of magnitude. Whether the same is true of horses isn’t known, but considering the horse has evolved to rely almost entirely on bacterial activity within the intestine for its existence, it’s almost certain that the numbers involved are even more impressive. But the bacteria (and other microorganisms such as viruses and fungi) don’t just provide the necessary enzymes to digest food — they have evolved with the host and are absolutely vital for the development and maintenance of other functions, particularly the immune and nervous systems. Even within the intestine, it isn’t just a matter of dissolving the food as it passes through for the animal to absorb: the microbes are fundamental to those pathways developing adequately and operating effectively, from the earliest stages of life to the very last day of it.

The most striking examples of the absolutely cardinal role of bacteria in health and development can be seen in laboratory animals. Mice can be born and reared in sterile conditions, so that they develop without any (or very few) microbes in their environment and without the normal gut colonies they would usually possess. These so-called germ-free, gnotobiotic, or axenic mice do not develop normally. They can be fed the optimum diet and housed comfortably but they do not thrive: their immune and digestive systems are stunted, they do not gain weight normally, and they are vulnerable to a wide range of diseases. Even if introduced to ‘healthy’ microbial populations found in conventionally-reared animals they do not recover, most likely because they have missed the aforementioned, once-in-a-lifetime, critical window. Interestingly, germ-free mice can live longer than their colonised compatriots (if reared very carefully), which has recently raised important questions over the role of the microbiome in ageing and its implications for humans. 

Mammals need microbes. So where does a new-born mouse, human, or foal get these essential organisms from and, knowing what we know about the dangers that some types of bacteria present, how do they get the right ones?

It is now established that babies born via caesarian rather than vaginal delivery are more at risk from a number of conditions, including inflammatory and neurodevelopment disorders, and diseases of the bowel, lungs and joints, so much so that the technique of ‘vaginal seeding’ has become a much-discussed technique. Much of the impact of surgical delivery has been attributed to alterations in the microbial community that the infant is exposed to in the very earliest stages of neonatal life. While caesarian delivery is a very much rarer event in horses, the effect of early exposure to the ‘correct’ microbiome (sometimes referred to as ‘pioneer colonisers’) has been demonstrated in other species. The hygiene hypothesis is a term used to describe the way that early exposure to particular microorganisms is protective, and that a lack of such exposure leads to poor immune tolerance. Unfortunately, this term has sometimes been misunderstood: it doesn’t mean hygiene is a bad thing — we all need protection from pathogens — and it certainly doesn’t imply that having more infections during early life is advantageous. But a broad exposure to a variety of certain microbes is an essential part of development.  

But this exposure may begin even earlier. For many years, it was considered incontrovertible that the foetal environment in utero was sterile and that exposure to bacteria and other organisms only began at birth. However, recent work has challenged this ‘sterile womb paradigm’ and a number of studies have demonstrated the presence of microbial material within placental and foetal tissues. The debate is still ongoing, not least around whether the presence of bacterial DNA actually represents viable bacteria or simply fragments of long-deceased organisms; even the ability to breed axenic animals (as mentioned above) suggests foetal microbial colonisation is unlikely. 

What is emerging is a general consensus that the products of bacterial life in the mother may well be influencing foetal development, and could be crucial to it. Maternal microbiota produce bioactive metabolites that can enter the maternal circulation and may be actively or passively transferred through the placenta.

We know that elements of the microbiome that affect offspring are transferable: for example, bacteria taken from the gut contents of obese mice and transferred to pregnant, normal-weight mice, lead to overweight offspring with altered inflammatory responses. Maternal obesity causes changes in microbiota correlated with altered foetal brain development, while maternal undernutrition in humans affects infant immunity by attenuating responses to vaccines in early childhood (among many other effects). There is a huge volume of data concerning nutrition, and its effects on offspring, across many species, and it’s beyond the scope of this article to go into direct nutrient effects. Nonetheless, work has shown that foals born to obese mares are more likely to be affected by osteochondrosis, and supports the hypothesis that maternal relative hyperinsulinaemia may be a contributory factor through its role in cartilage differentiation. Foals born to overweight dams also have evidence of systemic inflammation (higher levels of plasma SAA) which may also affect development through inhibitory effects on bone growth. Crucially, the impact on progeny may be different depending on the alignment of the disturbance: i.e. whether the mares were obese at conception or overfed during the early or later stages of gestation. Maternal undernutrition is much less likely to be a problem in commercial breeding operations, but when it is, mares may develop a syndrome close to gestational diabetes in humans, a condition widely recognised to have potentially very serious consequences to the neonate, and even beyond. Again, timing is crucial: studies of epidemics, famine, and war show that mothers and their children have different outcomes depending on at which stage, from preconception to early childhood, the crisis occurred. 

Maternal stress during early pregnancy has been shown to reduce faecal bacterial diversity and alter taxa composition in pregnant mice and has been replicated in human studies. Conversely, severe maternal stress in the last trimester was associated with increased bacterial diversity in newborn babies. Maternal depression may alter the ratio of certain bacterial families in neonates, specifically by reducing numbers of Proteobacteria, a pioneer taxon which creates the environment for later anaerobic colonisation. 

A number of studies have identified known risk factors for infant severe respiratory tract infections, the leading cause of child mortality globally, including a carbohydrate-rich, fruit-/fibre-/vegetable-poor maternal diet, and/or never breastfeeding. In a 2023 study, researchers demonstrated that mice fed high-fibre diets produced a milk microbiota that increased infant gut propionate levels, leading in turn to increased production of specific cells in the bone marrow that confer protection against respiratory infections. Indeed, therapy with specific propionate-producing bacteria, and even propionate supplementation, were shown to act in a similar way. Fermentable dietary fibre favourably influences the gut microbiome resulting in the production of metabolites that modulate the immune system (particularly short-chain fatty acids — SFAs). It is widely accepted that SFAs play an important part in regulating intestinal barrier integrity, and there is now evidence that they have a role in placental structure and vascularisation. Breastmilk also contains regulatory cytokines, growth factors and oligosaccharides, all of which influence the developing infant. Metabolic disorders, such as gestational diabetes, affect the levels of SCFAs and other metabolically significant metabolites causing changes in the maternal immune system with knock-on effects for the developing foetus. The authors of this study suggested that the “manipulation of the maternal diet during pregnancy and during the pre-weaning period, or through the provision of defined tailor-made prebiotics and/or probiotics directly to infants, may present novel opportunities for enhancing resistance to inflammation-mediated diseases.” Other researchers have described the transport of even more molecules across the placenta, including lipopolysaccharides and other bacterial cell fragments. Preconception infections with some intestinal parasites can lead to maternal imprinting in mouse offspring, thereby suggesting that the transfer of immunity is not solely dependent on the passive transfer of antibodies. 

These metabolites may also exert an effect on the genetic material within cells. Epigenetics is the set of factors and molecules that modify gene expression while not changing the genome sequence itself. Only around 2% of mammalian DNA is associated with protein-encoding genes; the rest (non-coding DNA — what used to be referred to as ‘junk DNA’) modifies the links on the chain to switch genes on and off at crucial junctures. These modifications are commonly associated with environmental cues — good and bad — that can result in significantly different outcomes (phenotypic plasticity) for two genetically identical individuals. In one Danish study, children who exhibited allergic rhinitis at the age of six were found to have a distinct DNA methylation pattern (an epigenetic signature) in their nasal mucosal cells associated with reduced microbial diversity at one week of life. It was folate’s role in countering the development of neural tube defects that first pointed to the foetal nutritional programming hypothesis through epigenetic programming. And as the stage most susceptible to environmental stressors is embryogenesis, where DNA methylation is closely associated with optimal differentiation and growth, consideration of preconception dietary factors is fundamental (folate supplements are recommended when pregnancy planning, but gut bacteria produce significant amounts of folate in humans with a healthy microbiome).

While epigenetic changes do not change the base-pair sequences within the genome, they are heritable, meaning that future generations may inherit far more than just the A–T and G–C building blocks. It seems certain that different epigenetic mechanisms may partly explain why dietary factors at critical developmental stages might affect the susceptibility to diseases in adulthood. 

With microbes contributing 99% of all genetic information present in the body, maternal microbial transmission should be viewed as an additional and important mechanism of genetic and functional change in evolution. Horses are selected for characteristics such as temperament, strength, speed, and endurance. Although genetic selection tools have been developed to assist breeders in the choice of sires and dams, there is also a growing body of research reporting that the maternal environment modulates the genetic potential of the offspring. Under natural conditions, microbes that promote host fitness, especially in females, will simultaneously increase their odds of being transferred to the next generation. Under controlled breeding programmes, efforts to assist this beneficial effect should be encouraged: the trajectory of the young foal’s colonisation process has lifelong clinical implications. And being aware of its influence may not only improve the outlook for your foal, but your foal’s foals as well. 

Guest Author

Why Broodmare Body Condition Matters

It’s common practice to maintain broodmares in what is considered “good condition.” In reality, this often means mares are kept overweight, based on the belief that heavier mares are more fertile.

But research and field experience suggest otherwise. Excess body fat in broodmares is associated with an increased risk of developmental orthopaedic disease (DOD) in their offspring, including:

• Osteochondrosis (OC)
• Osteochondritis dissecans (OCD)
• Angular limb deformities
• Flexural limb deformities

These conditions can significantly impact sale value, veterinary expenses, training timelines, and long-term soundness and performance outcomes.

The Hidden Problem: “Good Doers” & Nutritional Imbalance

When it comes to health and nutrition of broodmares, some of the most common issues I see in practice are:

• Misjudged body condition
• Underestimated nutrient requirements
• Over-reliance on pasture alone as a sole or primary feed source
• Haphazard or uninformed supplement use
• Feeding based solely on body weight and condition, not nutrient requirements

This is especially true for “good doing” mares. In an effort to control weight, many broodmares are not feed sufficient quantities of a suitably fortified feed or mineral balancer, meaning they:

• Lack key minerals needed for fertility, immune function and foetal growth and development (e.g. copper, zinc, calcium, magnesium, selenium, iodine)
• Receive inadequate micronutrient support
• May not consume sufficient amounts of essential amino acids such as lysine
• Still consume excess energy

This results is a mare that is overweight but undernourished. The implications of these don’t just impact her immediate health, but reproductive outcomes.

At the same time, supplemental feed, vitamin or minerals are often added without a clear understanding of:

• What the mare actually requires
• How her nutrient needs change from preconception, during the different stages of pregnancy, through to lactation
• Correct dosages
• How nutrients interact
• How any medications the mare may be receiving impact nutrient requirements 
• What is already being supplied through pasture and current diet

This can lead to:

• Nutrient imbalances
• Shortfalls in key nutrients required for optimal reproductive health and sound orthopaedic development of the mare’s offspring
• Excesses of nutrients that interfere with absorption of other minerals
• A false sense of “covering all bases”

More supplements generally don’t equate to better nutrition: precision matters. And when it comes to the healthy development of young horses, this is an area which you cannot afford to overlook.

Nutrition & Orthopaedic Development Are Linked

When managing DOD risk in young horses, nutrition and body condition cannot be separated.

All of the following may increase DOD risk:

• Overfeeding energy
• Poor gut microbial health (in both the mare and/or foal)
• Underfeeding essential nutrients
• Feeding certain minerals in excess
• Mineral imbalances
• Inconsistent feeding practices
• Sudden changes in feed
• Feeding in ways that promote high insulin levels

A foal’s orthopaedic health doesn’t start at birth: it starts with how the mare is managed before conception and throughout pregnancy.

The Real Cost of Getting It Wrong

Many developmental issues don’t appear immediately. Instead, they show up later as:

• Swelling, stiffness, lameness (sometimes only subtly)
• Radiograph (x-ray) findings
• Inconsistent performance
• Reduced athletic potential

By that point, the financial and reputational costs are significantly higher.

How to Get It Right

Optimising broodmare nutrition isn’t about feeding less or more, it’s about feeding in a way that promotes health and fertility in the broodmare and sound orthopaedic development in her offspring.

That means:

• Maintaining an appropriate body condition score (not overweight)
• Providing balanced minerals and trace elements in forms which the mare can readily digest, absorb and metabolise
• Adjusting feeding based on pasture, environmental conditions, and reproductive stage
• Ensuring energy (calorie) intake is appropriate given the mare’s unique requirements
• Taking a mare’s reproductive history into account and addressing specific nutrient requirements in relation to this
• Monitoring condition consistently and objectively
• Assessing and addressing the nutritional and metabolic impact of any medications a mare may be receiving 
• Feeding to promote optimal gastrointestinal health

Need Help Assessing Your Broodmare Program?

If you’re unsure:

• Where your mare’s body condition currently sits
• Whether her diet is properly balanced
• Specific nutritional requirements of your broodmare
• How to reduce DOD risk in your youngstock
• Why you mare may struggle with fertility or reproductive challenges, despite extensive veterinary intervention

Now is the time to address it, before small issues become expensive problems.

I work with breeders to optimise broodmare nutrition and management, supporting both fertility and the long-term soundness of their youngstock.

If you’d like a clearer understanding of where your mares currently sit and how to improve outcomes heading into the breeding season, feel free to get in touch.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Automatic watering troughs can seem like a great idea- helping ensure our horses have water available 24/7. In reality, however, many horses that rely on automatic watering systems, particularly small ones commonly found in stables and yards, actually have a high risk of being dehydrated.

There are multiple reasons why horses may not consume enough water from automatic troughs:

• They tend to refill at a slower rate than most horses drink. Many horses won’t remain at the waterer long enough to consume adequate water
• The noise or sensation of them refilling can scare some horses
• Many automatic troughs require an unnatural position for a horse to consume water from
• The water temperature can become excessively cold or overly warm (depending on the weather), which can discourage some horses
• The small, shallow design of many troughs can make it difficult for them to drink from
• Automatic troughs can be susceptible to stray voltage, giving horses an ‘electric shock’
• If they’re not cleaned regularly enough, they can smell and accumulate spoiled feed, insects, debris, algae, etc.

Ensuring our horses and ponies are properly hydrated is essential for their gastrointestinal  (GI) health– one of the many natural ways to help prevent the development of gastric ulcers and colic. Adequate hydration is also essential for overall health, performance and recovery.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Yet one factor which is commonly overlooked is hydration in our horses. Even subtle dehydration may increase their chances of developing gastric ulcers. But why is this?

Dehydration leads to reduced saliva production in our horses and ponies. Saliva plays an important role in protecting the stomach. Saliva is alkaline and rich in bicarbonate ions. Bicarbonate helps to buffer gastric acid, especially in the squamous (non-glandular) region of the stomach.

Dehydration also results in reduced mucosal blood flow- that is, blood flow to the lining of the stomach.  Compromised blood flow weakens natural mucosal defence and repair mechanisms making the stomach more susceptible to inflammation and ulceration. It’s commonly believed that horses only become dehydrated in hot weather, yet this isn’t true. Dehydration is common in very cold weather: research has shown that horses may drink less water when it is very cold. This can be compounded by a reduction of fresh pasture intake, when grass is under ice, snow or  its availability is sparse.

Inadequate salt in the diet is a common cause of dehydration in our horses.  As is the reliance upon the use of automatic watering troughs. Studies have shown that horses may not consume enough water due to the slow refilling time, small trough size, fear of the device, stray voltage which can give them an electric ‘shock’ when they go to drink or the unnatural drinking posture it requires.

Whilst ensuring our horses are consuming adequate water is essential to help promote proper hydration, it is vital to be aware of factors which may increase their loss of water and hint..it’s not just hot weather and sweating!

A horse who has diarrhoea or regularly has loose manure, has an increased likelihood of being dehydrated- even when their water consumption seems adequate. Medications such as furosemide (Lasix/Salix), ‘Kidney Flush’ products for horses (which are sometimes promoted as ‘urinary buffers’) and ertugliflozin (a drug which is very commonly used in cases of equine metabolic syndrome (EMS), insulin resistance (IR) and laminitis) may also cause dehydration in our horses.

From a management perspective, travelling our horses (even when the weather isn’t overly hot) and over-rugging/blanketing our horses can lead to significant fluid losses. As can diets excessively high in protein.

Being mindful of hydration,  particularly in horses with loose manure or those receiving certain medications, may be another simple but important step in reducing ulcer risk. Is hydration part of your horse’s gastric health checklist?

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

The composition of our hose’s gut microbiota has a profound impact on their behaviour and health. This is mediated through the gut-brain-immune axis. Changes in the composition of their gut microbiota can influence neurotransmitter production and function. Neurotransmitters are the natural chemical messengers which have important roles influencing many processes in our horses. Temperament, behaviour, motor control, learning patterns and digestive function are all influenced by neurotransmitters. Gut microbial population also affects neuroinflammation (inflammation of the brain and spinal cord), which can further influence mood and behaviour. Excessive levels of neuroinflammation may worsen stress, anxiety, tension and irritation in our horses.

Many things can adversely affect our horse’s gut microbiota, which may contribute to dysfunction of the gut-brain-immune axis. Clinical signs, changes and conditions we may see in our horses when their gut-brain-immune axis has been disrupted include:

• Faecal water syndrome
• Gastric ulcers
• Colonic ulcers
• Failure to thrive
• Failure to put on/maintain weight
• Susceptibility to infections and/or recurrent, chronic infections
• Nervousness, erratic behaviour, shying, anxiety, irritability
• Equine metabolic syndrome
• Insulin resistance
• Inflammatory bowel disease
• Colic
• Scours/diarrhoea
• Laminitis
• Osteoarthritis
• Equine Asthma Syndrome
• Recurrent skin conditions
• Poor recovery post exercise, training and/or competition
• Excessive muscle tension

In some horses, however, dysbiosis (unhealthy balance of the microbial community in the gut microbiota) may result in no obvious outward signs, yet their health is likely impacted under the surface, and this may become evident further down the track. Many of the signs associated with a dysfunctional gut-brain-immune axis health are non-specific, meaning they can often be dismissed or attributed to something else. Unfortunatel,y this means that often the underlying cause(s) of the condition or clinical signs can be overlooked in our horses.

Some of the factors which compromise GI health, and in turn influence immune health and behaviour include (but are certainly not limited to): insufficient dry matter (long-stem) fibre in the diet; large sized ‘hard feeds’ (ie concentrates and grains); large percentages of starch and/or sugar in the diet; abrupt changes in diet and/or pasture; the use of certain medications (including antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids and ulcer medications); viral and/or bacterial infections; high parasite burdens; nutritional insufficiencies, deficiencies and/or excesses (usually certain minerals, but sometimes particular vitamins); heavy metal toxicities; stress; pain; dehydration; high levels of inflammation in the body; extended travel; intense exercise.

Given the modern demands, management, feeding and medication use in horses, most horses will have compromises to their gut microbiota. The effects of these can be long-lasting, unless specific, targeted, supportive and corrective action is taken. This is crucial not only for their GI health, but in turn their immune health and behaviour, in addition to their overall health, performance and recovery.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

The way a foal enters the world can have a lasting impact on its gut health, immune function, and even its risk for developing inflammatory conditions later in life.

In the absence of infection, foals in utero have sterile intestines. 

The ‘healthy’ bacteria needed to colonise the foal’s gut microbiota primarily come from the maternal birth canal and rectum. Through the process of normal delivery, these bacteria are swallowed by the foal, travelling through the stomach and colonising the upper and lower intestine, a complicated process that evolves rapidly.

Foals born via cesarean section fail to encounter the bacteria of the birth canal and maternal rectum. Instead, bacteria from the skin and environment they are delivered in, quickly populate the bowel. As a result, the bacteria inhabiting the lower intestine following a cesarean birth can differ significantly from those found in the vaginally-born foal. Foals born via cesarean are likely to have different, less beneficial and health promoting bacteria to those foals born normally.

Through either mode of delivery, a core gut microbiota is well established within a few weeks of life. This bacterial balance persists largely intact throughout life. A less stable peripheral microbiota—one that is more sensitive to changes in diet and environmental factors, like antibiotics—is also formed.
In cases where cesarean deliveries are necessitated, there are strategies which can be employed to help establish and promote a healthier balance of microflora, thereby positively influencing the foal’s health for life.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

These bacteria play essential functions in our horses and ponies: they help to digest fibre through fermentation, providing our horses and ponies with a valuable energy source.

Through this fermentation of fibre, these bacteria also produce substances which have immune-supporting and anti-inflammatory properties. Importantly, some of these substances help to strengthen gut wall integrity and help prevent against the development of gastric and colonic ulcers. Additionally, these bacteria produce B group vitamins (including biotin) and vitamin K.

Fibre is a key component of our horses’ and ponies’ diets for their overall health, wellbeing and performance. Ensuring they are fed sufficient fibre is a dietary factor which is often overlooked, yet is arguably one of the most important feed related factors which influences every facet of their health.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Understanding pain in our horses

The experience of pain is unique to each individual horse and pony: in the way it presents, the intensity, frequency of the pain and how the horse or pony responds to treatment. In recent years, we have come a long way in better understanding the many different physical signs a horse or pony may display to indicate that they are in pain.

Pain seldom appears alone: it can impact a multitude of different aspects in a horse or pony. A horse or pony in pain can concurrently experience changes in behaviour or temperament: this may be one of the first indications which alerts us to the fact our horse or pony is experiencing pain. If the pain is new/acute in nature, these behavioural changes can appear totally out of character. If the pain is chronic/ongoing, the horse or pony may become withdrawn or ‘shut down’ in order to manage their pain. Poor performance, immune health challenges, digestive health issues and compromised fertility may all be associated with pain in our horses and ponies.

To effectively address and relieve pain in our horses and ponies, it is important to consider that pain can be multifaceted and complex. When we think of pain in our horses and ponies, we commonly think of pain which is a result of a direct physical cause. That is, pain that is associated with injury, lameness, poorly fitting tack or saddles, etc. This is what is referred to as ‘somatic pain’.

Yet pain can (and often is) so much more complex than this. Which in part, helps to explain why the use of anti-inflammatory drugs and corticosteroids doesn’t effectively resolve pain in many cases.

Different types of pain respond better to different treatments due to their varying mechanisms, mediators, impact on the brain and inflammatory pathways.

To provide the best pain relief for our horse or pony, an individual, targeted approach is essential. Read on to learn more about the different types of pain our horses and ponies can experience.  

Nociceptive Pain

Nociceptive pain is experienced due to ongoing activation of nociceptors (pain sensing neurones located within body organs and internal cavities). Nociceptive pain is caused by damage to body tissues as a result of trauma and/or inflammation. When we think of pain in our horses and ponies, nociceptive pain is generally the first type of pain that comes to mind.

Nociceptive pain serves as a protective response to injury or potential harm. In cases of chronic pain however, nociceptor activation can remain ongoing, even after healing of damaged tissues is complete and there is no further sign of damage/injury. Accurately identifying and understanding the causes and mechanisms behind this chronic pain in our horses and ponies can be incredibly difficult: an injury may be visibly healed (even on thorough imaging and diagnostic methods), yet the horse is still demonstrating signs of pain.

Nociceptive pain can be further divided into two main categories: somatic pain and visceral pain.

Somatic Pain

Somatic pain has a direct physical cause and arises from the musculoskeletal system (muscles, bones, joints, tendons, ligaments, connective tissues) and skin. Osteoarthritis, tendon injuries, ligament injuries, hoof abscesses, cuts and wounds are all examples where a horse or pony may experience somatic pain. It is what many vets, body workers, farriers and other equine health care professionals are often looking for when trying to identify the source of pain. In order to help identify the pain, lameness exams, nerve blocks, imaging (radiographs, MRIs, PET scans, CTs, nuclear scintigraphy etc) may be used.

Yet sometimes our horses and ponies still clearly demonstrate they are in pain, even when these avenues have been exhausted and there seems to be no explainable cause for their pain. So why is this? Despite the best technology, we can’t always see structural issues, so the pain can indeed be somatic in nature, but despite our best efforts, we can’t physically see what is causing the pain. Another reason, which may be overlooked, is the pain they are experiencing may not be somatic pain (or not just somatic pain alone). 

The pain our horses or ponies may be experiencing in this case is likely one (or a combination of) any of the other following types of pain.

Visceral Pain

Visceral pain is pain which originates from internal organs of the body, including the stomach, intestines, liver and kidneys. It may arise due to distension, inflammation or lack of blood supply to internal organs. Colic is a common clinical sign of visceral pain in our horses and ponies. The chronic, inflammatory nature of inflammatory bowel disease may cause visceral pain in some horses and ponies. In many cases we may not be able to visually ‘see’ the source of pain using diagnostic methods, instead relying on history and assessment of clinical signs in the horse or pony. Identifying visceral pain can be even more challenging as it may be masked by other conditions. The discomfort a horse or pony experiences from visceral pain can vary from mild to intense.

Neuropathic Pain

Neuropathic pain is what we commonly think of as ‘nerve pain’. It is caused by nerve damage or dysfunction, resulting in dysregulation of the transmission of nerve signals into the spinal cord. Many causes of neuropathic pain are often linked to excessive inflammation in both the peripheral and central nervous system. Inflammation however, is typically only one element of neuropathic pain. The pathophysiology of neuropathic pain is generally complex and multifactorial, which partly explains why the use of anti-inflammatories and/or rest may only provide minimal relief in many cases.

Central sensitisation

Central sensitisation is pain without identifiable nerve or tissue damage, which makes it challenging to diagnose. This type of pain is thought to result from persistent neuronal dysregulation. It may play an element in cases of neuropathic pain. Some types of neck and back pain without structural pathology may be examples of central sensitisation.

Inflammatory pain

Although somatic pain can definitely be a type of inflammatory pain, immune responses in our horses and ponies can also result in inflammatory pain. This may arise in cases of infection.

Referred pain

Referred pain is pain felt in a different location from the actual source. This form of pain can be challenging to diagnose. An example of referred pain may be highlighted by a horse or pony experiencing problems with its temporomandibular joint (TMJ) or teeth: in such cases, a horse or pony may have referred pain in the neck- with the neck appearing as if it is the source of pain itself.

Psychogenic Pain

Psychogenic pain is physical pain that is caused, increased or prolonged by emotional, mental or behavioural factors, without evidence of physical injury or illness. Psychogenic pain may not yet be commonly recognised as a clinical diagnosis in horses and ponies, but as we understand more about the role of stress, social isolation, anxiety, lack of freedom of movement, insufficient forage in the diet, boredom and frustration in the equine- the role of psychogenic pain should not be overlooked. From a clinical perspective, monitoring and/or observing signs such as heightened reactivity, increased heart rate and/or respiratory rate, stereotypies (wind sucking, cribbing, weaving, box/stall walking, paddock walking) may all be indicative of psychogenic pain.

So how can we help a horse or pony in pain?

In any case of a horse or pony experiencing pain, taking a thorough case history and conducting a comprehensive, holistic assessment gives us the best chance to understand the potential causes and contributing factors to their pain. It is important to note that in many cases, whilst clinical signs can be useful to help understand pain better in our horses and ponies, they are often non-specific.

Viewing, managing and treating pain from a holistic perspective gives us the best possible chance of helping our horses and ponies. We are fortunate that a wide range of judiciously employed nutraceuticals, herbal medicines, dietary and management strategies can significantly help horses and ponies who are experiencing pain. Within the scope of herbal medicine and nutraceuticals alone, we have multiple options in the choice of the herbs and nutrients which can be used to best help treat and manage different types of pain.

The treatment approach we take for specific types of pain should be different if we want the pain relief to be truly effective for our horses and ponies and to resolve the source(s) of the pain.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Corticosteroids (such as prednisolone and dexamethasone), non-steroidal anti-inflammatory drugs (such as phenylbutazone, firocoxib, flunixin), gastric ulcer medications and antibiotics all impact gastrointestinal (GI) ‘gut’ health through several different mechanisms. These may include: irritating the sensitive tissue which lines the digestive tracts of our horses and ponies, potentially causing gastric ulceration and/or bleeding; causing GI dysbiosis (adversely impacting the delicate microflora populations within our horses’ and ponies’ GI tracts); and altering nutrient absorption and metabolism (the way our horses and ponies digest, utilise and excrete nutrients). 

Good gut health is central to the overall health and wellbeing in our horses. We know that beyond digestive health, gut health in our horses and ponies significantly influences: immune health; bone, cartilage and joint health; respiratory/airway health; metabolic health; reproductive health/fertility; hoof health; laminitis risk; and even behaviour and motor patterns in our horses.

These are just some of the reasons why it is important to use any medications judiciously- even ones that are routinely employed in many situations. In the case that these medications are required, strategic nutritional supplementation and in many cases, appropriately prescribed herbal medicines can help to address some of the nutrient depletions and side effects caused by these medications. Additionally they can help to return the digestive system to the best possible state of health.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Many factors can contribute to developing colic and we know that in many cases, diet plays a significant role. What and how you feed your horse or pony can significantly increase or decrease their risk of developing colic.

Research has shown that a diet high in concentrates (ie mueslis, grain-based feeds) increases the risk of colic. In one particular study, horses fed a diet ‘high’ in concentrates (where ‘high’ was considered more than 2.5kg day- which in reality, is a small amount compared to what many horses are fed) had a significant increase in the risk of developing colic.

The more concentrate/grain or ‘hard’ feed a horse receives (and the less roughage they consume) the higher their risk of colic episodes. For every 1kg increase in concentrated feed per 100kg of body weight, the risk of colic increased by more than three times.

On the flip side, for every 1 kg increase in roughage (forage/hay) per 100 kg bodyweight fed per day, the risk of colic dropped by more than three times!

There are many likely mechanisms for the significantly increased/decreased risk of colic with the associated dietary changes.

The most important take-home question from the above is that what we feed our horses matters- not only for their performance, growth, body condition and health- but also in terms of increasing or decreasing their risk of colic.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

One welfare issue which may be associated with the use of gastric ulcer medications and which is commonly overlooked is rebound gastric hyperacidity.

Omeprazole and esomeprazole belong to a class of drugs called Proton Pump Inhibitors (PPIs). These drugs work by stopping the production of hydrochloric acid. Hydrochloric acid is a healthy, key component of normal digestive and immune function in our horses.

When we shut down the production of hydrochloric acid through the use of PPIs, we also interfere with our horses’ own negative feedback mechanisms which regulate hydrochloric acid production. When we stop the use of omeprazole or esomeprazole, particularly abruptly, as commonly occurs at the conclusion of a course of ulcer medication, or in racehorses, prior to racing- then rebound gastric hyperacidity may occur. That is, for a period of time, their bodies lose the ability to regulate the amount of hydrochloric acid produced, resulting in a production of excessive amounts.

This in turn, can increase the risk of EGUS and feed into a self-perpetuating cycle: where a horse is put on ulcer medications, and may (or may not) experience some relief in clinical signs, believed to be associated with EGUS, before coming off the medication and reverting to displaying clinical signs and/or developing EGUS

The use of ulcer medications in any instance should be critically evaluated and when prolonged use is felt necessary, the contributing factors to the development of EGUS should be addressed.

EGUS is often considered a ‘man made’ disease in our horses and ponies: that is, it occurs largely due to our feeding, management and medication practices. The good news is that there is much which can be done to help treat and prevent further episodes of EGUS: Through changing what and how we feed our horses; managing our horses in a way that is conducive to good gastrointestinal ‘gut’ health; providing therapeutic support where appropriate; and reviewing medication practices.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Salt (sodium chloride) is absolutely essential for our horses and ponies. Salt helps to promote: thirst response (so our equines remain adequately hydrated); fluid balance; healthy blood pressure; and normal muscle and nerve function; and is needed for healthy digestion and gastrointestinal (GI) function.

Salt toxicity is extremely rare in horses, provided they have access to unlimited clean water. 

Research conducted in other animal species and humans has shown that excessive intakes of salt, however, can cause dysbiosis (adverse changes in GI microflora). 

Although currently there is no equine specific research on the topic, it does pose the question ‘can we give our horses too much salt?’  

Whilst this is unlikely, it is possible: an example may be where multiple and/or high dose electrolyte supplements are used, particularly in relatively inactive horses and/or those who don’t sweat much.

In clinical practice, I rarely see horses who have excessively high salt intakes: it is very common however, that I see horses who do not receive sufficient salt in their diets.

Furthermore, horses who are receiving ulcer medications (those containing omeprazole, in either oral or injectable form) can have changes in sodium chloride levels. These drugs interfere with salt absorption- meaning our horses aren’t able to utilise all the salt we are feeding them. This can have repercussions in terms of both health and performance.

Ensuring our horses receive adequate salt relative to their individual requirements and taking into account factors such as medication use is crucial for their wellbeing and performance.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Poor fertility rates or sub-optimal fertility in stallions can be one of the most financially costly and frustrating challenges for breeding studs and managers.

Sometimes the cause(s) of poor fertility rates can be obvious. Yet, more often than not, the contributing factors may not be clear.

Stress is something which can be easily overlooked, yet plays a fundamental role in the reproductive health and performance of stallions. Stress has been found to reduce luteinizing hormone and testosterone pulsing, leading to reduced spermatogenesis and sperm quality.

The presence of stress in a stallion can be deceptive…When we think about stressed horses, we may commonly think of an outwardly anxious horse; a horse who is always alert and ‘on edge’; one who is reactive and sensitive to changes in their environment; who doesn’t settle easily; and who may walk or pace their paddock. Whilst these are all easily recognisable outward signs of stress, a horse can be under significant stress yet paradoxically appear calm and relaxed.

Some less commonly considered sources of stress to our stallions which may impact their fertility include:

• Nutritional deficiencies and/or insufficiencies;
• The side effects of many commonly used medications;
• Irregular feed regimes
• Insufficient grazing and/or provision of roughage in their diet
• Shuttling and extended travel
• Changes in a stallion’s environment
• Pain- some examples include musculoskeletal pain when covering or gastric ulcers
• The presence or absence of other horses in their immediate environment
• Excessively hot environmental conditions

Even the way a stallion is handled can impact his stress levels. On busy studs, it is not uncommon to be in a rush to complete coverings within a certain time frame. If handlers are stressed, anxious, rushing or feeling pressure to complete breeding sessions, this can raise cortisol levels and heart rates in our stallions, leading to a physiological state of stress.

Whilst we certainly can’t control all the factors which contribute to stress in a stallion, there are many aspects which are modifiable through the way we look after and manage our breeding stallions. Furthermore, the strategic use of appropriate nutritional supplements and herbal medicines can help to mitigate some of the negative effects of stress and help improve testosterone levels, sperm count, sperm quality, sperm morphology and progressive forward motility.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Objectives: To describe the successful treatment of two cases of LPE with differing presentations that underwent thorough diagnostic evaluation and failed to respond to conventional therapy. The importance of addressing the gut microbiome- immune system axis is emphasized.

Study design and data collection: Retrospective analysis of medical records. Case details and setting: Case one: a 10-year-old Quarter Horse gelding with diffuse LPE confirmed by laparoscopic biopsy. Case two: a 12-year-old miniature gelding with diffuse LPE diagnosed by intestinal biopsies and transabdominal ultrasonography. Both horses had undergone repeated extensive physical examinations, gastroscopy (with no lesions evident) as well as complete blood counts and basic metabolic panels. Case two had undergone faecal egg counts and microbial culture. Both horses were resident in Australia. Case one presented with a 15-week history of lethargy and depression, ventral oedema extending from the jaw to the prepuce and daily episodes of mild to severe colic. Colic events were managed with per os administration of flunixin meglumine, but not always successfully. Daily medication consisted of oral dexamethasone, omeprazole and vegetable oil. The horse was also receiving a proprietary GI- specific dietary supplement and had previously been treated with sucralfate. Complications with wound healing following the laparoscopy had necessitated an extended period of hospitalization. Case two presented with sudden onset, profuse watery diarrhoea of 2 years ‘duration; bruxism; intermittent passing of mucus; lethargy and sporadic inappetence for hard feed. At the time of assessment, 8 weeks after LPE diagnosis, the gelding was receiving daily oral doses of dexamethasone, omeprazole and codeine. Previous treatments included a five-day course of benzimidazole followed by single doses of moxidectin and praziquantel; bentonite; yoghurt; oral faecal transplantation; misoprostol; corn oil; psyllium husk; phenylbutazone; sucralfate and antimicrobials (metronidazole and sulfadiazine/trimethoprim).

Intervention: Case one received treatment with an ethanol-based preparation of astragalus, echinacea, chamomile, cramp bark, ginger and liquorice in combination with glutamine, zinc citrate, vitamin D3, slippery elm bark and a multi-strain probiotic. The vegetable oil was stopped immediately. A compound of corydalis, California poppy, valerian and cramp bark was used to manage colic episodes, as required. After 1week, the gelding was weaned off the dexamethasone and omeprazole. The diet was modified to increase dry matter and hard feed meal sizes were reduced while the horse was transitioned to a grain-free diet. Walking exercise was introduced and the owner was encouraged to leave the horse without rugs/ blankets. Case two was administered an ethanol-based blend of goldenseal, meadowsweet, echinacea, corydalis, aniseed and ginger alongside glutamine, zinc citrate, vitamin D3, slippery elm bark and a multi-strain probiotic. Concentrate feed and oaten chaff were withheld temporarily, with lucerne and teff hay quantities increased. Dexamethasone, omeprazole and codeine were gradually curtailed while hand walking was introduced and the pony was left without rugs/blankets.

Results: Case one: 24- h video surveillance confirmed significant reduction in severity and frequency of colic episodes within 2 weeks. The ventral oedema resolved after 4 weeks, with noticeable improvements in perceived energy levels. The gelding has had no recurrence of oedema for 20 months and has been colic-free for 14 months. Competition use has resumed. Case two: within 3 weeks bruxism had ceased, there was a notable improvement in manure density and markedly improved energy levels. After 3 months, faecal output was normal on most days and a grain-free balancer feed and lucerne chaff were introduced, which the pony readily consumed. By 5 months manure density was normal, and has remained so after 2 years.

Main limitations: Biopsies were not repeated after treatment and recovery; efficacy of treatment based on observation of clinical signs; small case numbers.

Conclusion: Chronic LPE, including cases unresponsive to pharmaceutical intervention, can be stabilized and treated successfully by integrating nutraceutical, herbal medicine, dietary and management strategies.

­Ethical animal research: No ethical approval required.

Funding information: None.

Conflict of interest statement: None.

Reference:

Vitale, V. (2022) Inflammatory bowel diseases in horses: What do we know? Equine Vet. Educ. 34, 493–500.  

Published in Equine Veterinary Education Volume 36 | Supplement 13 – Link

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Whilst we are always aiming to do what is best for our stallions, sometimes commonly used medications, supplements and routine management practices can hinder the very outcomes we are trying to achieve.

One such example is the use of gastric ulcer medications in our stallions- whether for the treatment of existing ulcers or with the belief that the use of such medications will help to prevent gastric ulcers.

The drug omeprazole is considered the gold standard pharmaceutical treatment of equine gastric ulcers- and is the key ingredient of the vast majority of ulcer medications on the market.

Research has demonstrated that omeprazole can reduce male fertility through multiple mechanisms: impaired sperm quality, abnormal sperm morphology, reduced sperm motility and reduced sperm count. Omeprazole may also cause a reduction in serum testosterone levels.

When every pregnancy counts and significant revenue is at stake, critically reviewing the use of such medications should be forefront.

There are other effective alternatives available to aid in healing and/or preventing gastric ulcers in horses. Furthermore, through individualised application, the potential exists to also concurrently significantly enhance stallion fertility and overall health.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

But do probiotics for horses provide any benefit? Do they actually work? And what do we need to be aware of?….

The current research regarding probiotic supplementation in equines is quite limited. Studies have shown mixed results about their use: some probiotics may be beneficial in some cases; some may have adverse effects on the health of our horses. A good example of this is some cases of diarrhoea may be worsened with the use of some types of probiotics.

Yet there are currently so many gaps in our knowledge of the equine gastrointestinal microbiome and so many variables which can influence the effects which probiotics may have in our horses and ponies.

Before using probiotic containing feeds or supplements in our horses, the following points are worth considering.

Some common (yet rarely discussed) limitations/drawbacks of the addition of probiotics for horses in feeds and supplements are:

• Heat exposure. Many (but not all) probiotics for horses are only stable and remain viable within a certain temperature range. If a feed is produced using heat (as many processed feeds are) and the probiotic is exposed to heat during the cooking process, then the probiotic may not survive.

• Similar to the above, certain types of probiotics are incredibly sensitive to temperature. For these types of probiotics, if they are not kept in cool enough conditions (ie refrigeration), then the probiotics may not remain live or viable.

• Before we purchase the probiotic, how do we know the product has been kept in/stored in suitable conditions to allow that probiotic to remain live? Many feeds and supplements sit in warehouses, shipping containers, etc- which are often hot, and in turn, can compromise the integrity and efficacy of the product.

• Many strains of probiotics used in horse products fail to include strain identification. Different strains of probiotics have different therapeutic properties- and don’t necessarily correlate with human probiotic use and benefits.

• Many probiotic products don’t contain a sufficient number of probiotics (furthermore, it is quite common for horse feeds and supplements to not disclose individual counts of probiotics in their products). Without knowing the number of certain strains of probiotics in a product, we don’t have the information necessary to dose the product correctly to be clinically effective.

• Are the probiotics we’re using resistant to stomach acid and bile salts naturally produced by the horse? If not, they have little chance of reaching the hindgut and colonising it adequately.

• Are the probiotics in the formulation able to adhere to the intestinal wall to properly colonise and exert their effects long-term?

• Some probiotics for horses may have the potential to influence the efficacy of certain types of antibiotics.

Whilst probiotics may be beneficial in the prevention, management and/or treatment of specific health conditions in horses, careful consideration needs to be given before using them. Not all probiotics are created equally, and sometimes seemingly innocuous supplements can work against the desired health outcomes we are trying to achieve in our equines.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Foals and coprophagy

Foals will generally start consuming manure from about five days old. It is common for this to occur up until approximately three months of age, before gradually declining. By 19 weeks of age, the habit generally stops in most foals.

By consuming manure, foals are populating their digestive system with a variety of microbes: bacteria, protozoa, archea and fungi. This habit is thought to be an important part of healthy gastrointestinal and immune system development: foals are born with a relatively ‘immature’ microbiome which is influenced by multiple factors in their early stages of life. It is worth keeping in mind however, that if a foal is consuming manure from a horse with poor digestive health and/or a horse with a poor balance of microflora and/or a horse with a high parasite burden then this may potentially have adverse effects in the foal.

Inferred research from other animal models suggests that a mare’s faeces contains a pheromone which encourages the foal to consume the manure.  Deoxycholic acid is believed to be present in a mare’s manure: an important byproduct of intestinal bacteria which supports digestive system immunity (helping to protect against enteritis). Deoxycholic acid may also facilitate normal neurological development through promoting myelination of nerves.

Adult horses and coprophagy

The consumption of manure in horses and ponies older than foals is considered an abnormal behaviour. When it does occur, it is thought to be primarily diet and/or gastrointestinal (GI) health related.

A diet low in dry matter fibre (often referred to as ‘roughage’) is one of the most common reasons a horse may consume manure. It is a common misconception that pasture alone provides enough fibre for our horses and ponies, but grass is very low in dry matter fibre. Without feeding appropriate amounts of hay or alternative dry matter fibre sources, the vast majority of horses and ponies will fail to meet their requirements.

Other diet related factors which may contribute to coprophagy include:

• Diets high in starch: even when there is adequate dry matter fibre in the diet;
• Underfeeding and/or food scarcity;
• Long periods of time without access to feed (for example, going more than three hours without access to hay/pasture and/or hard feed);
• Poor gastrointestinal (GI) microflora populations (diet related);
• Specific nutrient insufficiencies and/or deficiencies: potentially vitamin K, selenium and/or zinc.

Dietary factors aside, anything that significantly disrupts a healthy GI microflora balance can contribute to coprophagy. This can include the use of many common medications (such as antibiotics, non-steroidal anti-inflammatory drugs; corticosteroids, gastric ulcer medications); stress in all of its many forms (!); dehydration; travel, etc.

Other less common reasons an adult horse may consume manure can include medical conditions such as equine motor neurone disease.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

In addition to compromising the health, vitality, growth and immune function of the foal, Rotavirus has been associated with gastrointestinal ulceration in foals.

This is likely due to nutritional and systemic stress, interruption of suckling in foals and the direct damage the virus causes to the epithelial cells which line the gastrointestinal (GI) tract.

In addition to appropriate veterinary treatment (where required), strategic use of appropriate nutritional supplements and herbal medicines can help restore integrity to the digestive system, support immune function, and optimise the health and growth rate of the foal.

It is worth keeping in mind that commonly prescribed ulcer medications (those containing omeprazole or ranitidine) can adversely impact nutrient availability- including key nutrients needed for both immune function and proper restoration of the GI epithelial lining. To learn more about the effects of ulcer medications visit Ulcers in Horses: The importance of understanding how medications work.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

But there’s so much more to hoof health than biotin, and if we just focus on one nutrient we miss an important opportunity to help improve not only our horse’s hoof health but their overall health.

It’s also worth remembering that horses with a healthy hindgut microbial population are able to synthesise their own biotin.

Gastrointestinal (GI) health

Poor hoof health can often be indicative of poor gastrointestinal health and/or nutrient deficiencies and/or inadequacies in their diet.

Good gastrointestinal (GI) health in our horses is central to their overall health. The integrity of the cells lining the GI tract, the types and numbers of specific microbes which inhabit the digestive tract and the production of special enzymes within the GI tract all play key roles in many facets of their health.

Long-stem fibre should form the foundation of our horses’ and ponies’ diet: yet fibre intake in many equines falls well below the minimum recommended requirements.  Fibre passes through a horse’s stomach and small intestine undigested, where it reaches the large intestine. Here it undergoes bacterial fermentation by special types of microbes (note: it is normal and healthy for horses to digest fibre in their hindgut, it is not healthy for them to ferment undigested grains and starches). The fermentation of fibre by these microbes results in the production of various substrates important for immune, gastric and nervous system health in our horses. Some of these healthy microbes also produce biotin. A horse with a healthy hindgut microbial population who is fed adequate fibre, can synthesise good levels of biotin needed for hoof health. To read more about the importance of fibre in our horses’ diets, see: Grass, Hay, Fibre and Short Chain Fatty Acids.

Many other nutrients are required for healthy hooves: sufficient quality protein (including adequate amounts of the amino acids lysine, methionine and choline read more about the importance of protein here);  copper; zinc; iodine; calcium; selenium; B group vitamins; vitamin E; vitamin C and vitamin D. Some of these need to be provided in a horse’s diet. Others such as B group vitamins, vitamin C and vitamin D a horse can synthesise if given the right conditions. Simply supplementing biotin alone without ensuring other nutrient needs are met is of limited value. All the aforementioned nutrients also play various key roles in other facets of our horses’ and ponies’ health: fertility; metabolism; immune health; joint and musculoskeletal health; neurological function and behaviour.

Anything that interferes with a healthy GI microflora population in our equines, and/or interferes with the integrity of the cells lining the GI tract, in turn influences nutrient absorption and/or metabolism. Ironically, some of the things which interfere with digestive function are often used to help counteract digestive or other health complaints: gastric ulcer medications; antibiotics, non-steroidal anti-inflammatory drugs and corticosteroids to name a few. To learn more about the influence of ulcer medications in relation to the overall health of our horses, visit: Ulcers in Horses: The importance of understanding how medications work.

It’s worth considering the aforementioned aspects before trying to solve an issue such as poor hoof health by adding more supplements to a horse’s diet. If a horse or pony isn’t consuming sufficient fibre or nutrients, and/or is unable to properly digest, absorb or utilise specific nutrients, then adding more supplements to their diet is unlikely to provide an effective solution to the issue at hand.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

In recent years, much attention has been given to grain-free feeds. Low-GI, low starch, ‘calming’ and low sugar feeds also get plenty of airtime. All the terms can relate to different aspects of the feed, but in the majority of cases, it is clever marketing and doesn’t ensure that the feed we are purchasing is necessarily suitable or safe for our horses and ponies.

Clever marketing and loopholes in claims that can be made on feed packages can become very confusing. Feeds can claim to be ‘grain free’, a ‘calm performing feed’ or low GI, yet in some cases the predominant ingredients in the feed may be made from grain! If we take a look at an ingredients list (remembering that ingredients are ordered in descending order of the percentage they make up of the feed) grain may be present in the form of millmix, millrun, pollard, cereal by-products, wheat middlings to name a few! Other products may be truly grain-free but contain large amounts of molasses and other high-calorie oils and ingredients to bind the feed together and/or make it more palatable. In either case, for many horses with metabolic issues, these feeds are likely to not be suitable. Generally ‘grain-free’ refers to the fact that no whole grains are present, yet many of these feeds contain processed grain ingredients- which certainly doesn’t make them grain-free! Along the same lines, there are feeds widely available in Australia that are advertised as suitable for horses with ‘grain intolerance’ which have barley or millrun as the predominant ingredient in the feed!

There are many reasons why it may be preferable to feed a horse or pony a truly grain-free diet, particularly a diet low in starch and sugars. For many equines, they don’t need the calories/energy provided by such grains and concentrated feeds, and in the case of horses with equine metabolic syndrome, insulin resistance and many cases of laminitis and Pituitary Pars Intermedia Dysfunction (PPID) (formerly known as ‘Cushings’), steering clear of grain is generally a good idea.  For other horses with higher calorie needs, the incomplete digestion of grain products and the resulting fermentation of starch and sugars in the hindgut can increase the risk and/or severity of gastric and colonic ulcers, inflammatory bowel disease, ’tying up’, developmental orthopaedic diseases (such as OCDs and bone cysts), immune dysfunction, inflammatory conditions and behavioural issues.

If a horse needs to be on a grain-free diet, and more specifically a low starch and sugar diet, we need to pay particular attention to all the ingredients contained in a feed, as well as the feed’s nutritional analysis- not just the marketing claims! We also need to remember that a horse’s or pony’s ‘hard feed’ should only make up a small percentage of its diet. We need to consider the role which pasture and hay play in each equine’s intake: from the perspective of calories, starch and sugar. Additionally remember that for multiple health reasons, long-stem fibre (such as that found in hay) should form the basis of their diets. To read more on the importance of fibre and hay, see the articles Fibre, Chewing and Gastrointestinal Health; Why Basics Matter: The Importance of Chewing; Hay, Stomach (Gastric) & Hindgut (Colonic) Ulcers; and Grass, Hay, Fibre and Short Chain Fatty Acids. 

What and how we feed our horses and ponies plays a crucial role in their overall health. In many cases, we can mitigate the risk of severe health conditions, whilst also ensuring that we are giving our equines everything they need to perform at their best and be in the best of health. Clever marketing and loopholes in regulations governing feed claims can make it both challenging and confusing to feed your horse or pony in a way that is best for each individual equine. Seeking independent advice from suitably qualified and experienced nutritionists and equine health practitioners is one of the best investments you can make in your horses’ health and performance. Prefer listening to podcasts or watching webinars to learn more about equine nutrition, gut health, ulcers, immune health and other horse health conditions? Be sure to visit our Media page for plenty of informative recordings.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

In short, it relates to the microbiota of our equines’ digestive systems.

The bacteria, fungi, protozoa, and viruses that colonise the equine gastrointestinal tract (GIT) (collectively known as the microbiota), play many crucial roles in horse health.

These microbes influence digestion, energy and nutrient production, immune health, levels of inflammation in the body, overall GI health, body condition, respiratory health, skin health, metabolic health, reproductive hormones and the production of neurotransmitters (chemicals which influence their mood, temperament, learning, motor control and behaviour).

When the microbiota deviates away from what is optimal, a horse is more susceptible to conditions of inflammation, illness, pathology, GI disturbances including colic, gastric and colonic ulcers, stressed behaviour and diminished nutrient and energy production and uptake.

The large population of microbes that inhabit the equine GI tract are influenced by what our horses and ponies eat. The specific types of microbes become accustomed to what our equines are fed and must adapt to different types of feed. This means that when they eat different types of feed, there are different populations and types of microbes.

Sudden dietary changes induce rapid shifts in this delicate balance of microbes and the byproducts they produce, rendering a horse more susceptible to illness. Whilst this is a broad simplification, the sudden changes in the microbes and their activity are largely indicated in many cases of colic, laminitis and other serious health conditions.

When we add new feeds to a diet or change a horse’s diet- we want to facilitate a gradual change in the microbial population and the products these microbes produce. The best way to do this is to introduce new feeds into their diet gradually over a 7-14 day period, slowly increasing the amounts of the new feed as the microbial population adjusts.

It’s a simple process, which is largely overlooked: something which can save a lot of pain, heartache and expense.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

With plenty of fresh pasture available, it can be tempting to stop feeding or reduce the amount of hay we give our horses. Yet if we want them to have good gastrointestinal (GI) ‘gut’ health, then keeping feeding sufficient hay to them is a must! To learn more about the important role of hay in the diet, visit the article: Hay, Stomach (Gastric) & Hindgut (Colonic) Ulcers.

Green grass is predominantly water and as a result, is low in dry matter fibre. Dry matter fibre is incredibly important for our horses and ponies for a multitude of reasons. Dry matter fibre supports the proliferation of and helps to maintain a healthy GI microflora population. To read more about fibre, see Fibre, Chewing and Gastrointestinal Health.

Dry matter fibre is also needed for the production of short chain fatty acids (SCFAs) also known as volatile fatty acids (VFAs). Short-chain fatty acids are predominantly produced by the fermentation of fibre by the GI microbiome.

These SCFAs have many health benefits, including significant anti-inflammatory and immune-regulating properties. Furthermore, they help to promote the production of specific neurotransmitters (chemical messengers) which help our horses to be calm and relaxed. They have also been shown to help decrease fat accumulation and improve insulin sensitivity (an important consideration with insulin resistance, laminitis and equine metabolic syndrome (EMS)). 

From a direct gut health standpoint, SCFAs play a crucial role to help promote proper GI barrier function- thereby helping to protect against the development of gastric and colonic ulcers. To read more about ulcers, see articles: Hindgut (Colonic) Ulcers in Horses and Ponies; and Ulcers in Horses: The importance of understanding how medications work.

Sometimes the simplest things can make the most profound difference in helping the overall health of our horses and ponies. Adequate fibre is one important dietary measure we can put in place to help promote calm behaviour in our horses, support sound bone and joint health, reduce inflammation, and reduce the risk of laminitis, insulin resistance and EMS.

Prefer listening to podcasts or watching webinars to learn more about gut health, ulcers, immune health and other equine health conditions? Be sure to visit our Media page for plenty of informative recordings.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

And whilst all these can be examples of a horse or pony which is stressed, sources of stress and the effects it has on their body can encompass so much more.

We can actually have horses and ponies who in their nature are very relaxed and settled, yet their body is under significant stress. Stress is a type of change that causes physical, psychological or emotional strain in our horses.

Multiple forms of stress can have a cumulative effect, creating significant demands on the bodies of our horses. As a result of ongoing stress, our equines have increased requirements of particular nutrients.

Stress is also an important consideration in relation to stallion fertility, pregnancy in mares, gastric and colonic ulcers, inflammatory bowel disease (IBD), laminitis, insulin resistance (IR) and equine metabolic syndrome (EMS), chronic infections, bone health and failure to thrive.

Some of the many different sources of stress to our equines include:

• Separation/Isolation
• Injury
• Illness
• Use of certain medications
• Nutritional deficiencies/insufficiencies
• Nutritional excesses
• Travel
• Dehydration and/or withholding water
• Withholding feed
• Weaning
• Pain
• Inflammation
• Intense exercise
• Parasites
• Heavy metal burdens
• Exposure to chemicals, pesticides

What other sources of stress can you think of?

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Salt is a mineral which remains an important part of the diets of our equines year-round, yet is easily overlooked. Most fortified feeds on the market don’t contain enough salt to meet the needs of our horses and ponies. If we’re not actively providing salt to our equines, then they’re likely falling well short of their requirements.

Salt is an electrolyte which helps to maintain fluid balance and hydration. It is continually lost through saliva, urine and sweat, so, therefore, must be provided in the diet to be replenished. Horses need salt on a daily basis, even when they’re not visibly sweating.

Salt is needed for proper functioning of the nervous system, digestion, balancing pH levels in the blood and helping muscles to function correctly.

Sodium also stimulates the thirst response in our horses and ponies. Without adequate salt in their diet, many equines will not drink enough water. This is one of the many important factors to consider in horses who have suffered from spasmodic or impaction colic, where gastrointestinal (GI) motility and/or dehydration play a role.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Another way is how they position themselves during cold, wet and/or windy weather. Read more about this by visiting Why do horses and ponies turn their backs to the cold during inclement weather?

Another important aspect of helping our equines keep warm during cold weather is how and what we feed them. The digestive systems’ of horses and ponies can significantly contribute to keeping them warm.

Our horses’ and ponies’ hindguts house trillions of microbes (including bacteria and other microorganisms). These microbes play a key role in many facets of equine health: they influence immune function, inflammation, behaviour and temperament, and nutrient status. When we feed our horses and ponies high fibre diets (particularly long stem fibre found in hay) we help to promote a healthy balance of these microbes.

The microbes digest (ferment) the fibre found in hay, pasture and other fibrous feeds to produce energy in the form of volatile fatty acids (VFAs). These are also referred to as short chain fatty acids (SCFA).

Heat is a by-product of breaking this fibre down. In turn, the fermentation of fibre can provide a significant amount of energy (calories) to our horses. Further heat is also produced by chewing: the more time a horse spends chewing, the more heat is produced. Eating 1kg of hay requires four times as much chewing and takes four times as long as eating 1kg of oats or grain! This also has additional effects in helping to protect against gastric and colonic ulcers. To read more, see the articles: Hay, Stomach (Gastric) & Hindgut (Colonic) Ulcers; Why Basics Matter: The Importance of Chewing

Feeding our horses and ponies sufficient hay (at a minimum 1.5% of their body weight in dry matter daily) is one of the most natural and easy ways to help keep them warm in the winter. As an added bonus, feeding them this way in turn helps to promote a healthy gastrointestinal microflora balance: resulting in a flow on of multiple positive health benefits.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Many factors can potentially contribute to idiopathic colic episodes: consumption of tainted/mouldy feed or hay; diets low in roughage (hay and/or fibrous feeds); high grain diets; sudden changes in feed; high parasite burdens; excessive stress; and long-term use of NSAIDs (such as flunixin, ‘bute/PBZ’). 

Whilst all these factors play a unique role in their contribution to increasing the risk of colic in the horse, they all share a commonality: they significantly alter the microflora balance of the gastrointestinal tract (GIT) of our horses. This in turn can play a key role in the development of colic. To read more about the effect of NSAIDs on GI health, visit the article: Inflammation & Non-Steroidal Anti-Inflammatories in Horses

In light of this, it is important to consider other factors which unfavourably alter gastrointestinal (GI) microflora (such as the use of antibiotics and corticosteroids) when evaluating the cause of colic. 

In the case of influences such as the aforementioned medications, it is important to remember that colic is unlikely to result from immediate use: it may be some time after that the horse has a seemingly ‘unrelated’ or ‘inexplainable’ case of colic. This is due to the increasing imbalance in GI microflora, which was first initiated by the medication.

In clinical practice, I see many referred cases of horses who have repeated idiopathic colic episodes who have been on long-term ulcer medications (generally those containing omeprazole, and sometimes those containing ranitidine). These medications interfere with proper digestion of feed, commonly resulting in fermentation of starch and grains in the hindgut, resulting in excessive production of gas. The use of these medications can also significantly impact a horse’s natural, healthy balance of GI microflora. To read more about the effects of ulcer medications on GI health see articles: Hindgut (Colonic) Ulcers in Horses and Ponies; Ulcers in Horses: The importance of understanding how medications work; and Ulcer Medications: What Nobody Tells You and What You Need To Know.

Colic can be a fatal condition in our horses and ponies, and it can be frustrating when the cause of colic is unknown. Taking the time to assess potential contributing factors, including those which influence GI microflora are important steps in helping to prevent colic episodes.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

For the owner or rider considering taking on an OTTB, careful thought and planning should go into ensuring that the transition from the life of a racehorse to the next phase of the horse’s career is as smooth as possible. Some of the biggest considerations need to be given to changes in the horse’s diet, routine and optimising health parameters. Equipping yourself with knowledge and enlisting the help of suitably qualified professionals can help to realise your horse’s full potential.

Goals and Capabilities as a Rider/Handler

Before even inspecting an OTTB for potential purchase, clearly know what you are wanting in your new horse and your capabilities as a rider. Are you looking for a future show hack with impeccable conformation and looks? Are you looking for a pony club mount that needs to be calm and versatile? Are you looking for a horse with the potential to be a top-class eventer, thereby needing to be very sound, athletic and able to withstand high levels of training? Are you looking to get a cheap yet athletic horse to re-educate and sell on? Knowing the answers to these questions will quickly help to narrow down the horses you inspect for potential purchase and look to undertake a pre-purchase veterinary examination. By clearly knowing your goals, you can save yourself a lot of time and money and are far more likely to choose the most suitable horse.

When taking on an OTTB (particularly one that has come straight from a racing stable environment), honestly assessing your capabilities as a rider is critical. Are you confident and competent enough to safely and effectively manage and deal with an anxious, highly geared horse (whose temperament may or may not change significantly whilst in your care)? Or are you better suited to taking on a more relaxed OTTB or even one that has been off the track for some time and has spent time being re-educated with a different owner? One of the many beauties of OTTBs is that there are so many to choose from and at many different life and career stages- you are bound to find one that suits you perfectly! Be patient and choose wisely.

Vet Check

One of the first things to consider (and often most overlooked) when purchasing an OTTB is getting a thorough vet examination prior to purchase. Musculoskeletal soundness and airway health are two of the most significant considerations. Just like human athletes, racehorses’ bodies are put under strenuous physical demands, with the potential to develop injuries. Due to the hard galloping done by many young horses in training, considerable stress is put on bones, tendons and ligaments. This can lead to soundness issues. A thorough vet examination can help to identify previous injuries or any potential issues which may influence the ability of the horse to be suitable for its intended next career. On radiographic screening (x-ray), many racehorses will have some degree of osteoarthritic changes in their joints. With planning, sound dietary practices and the strategic use of appropriate supplements and management interventions, many of these conditions can be well managed. Furthermore, the fact that many OTTBs transition into their next careers at a relatively young age is advantageous. From a physiological perspective, when given suitable nutrition and support, their body is better able to repair and regenerate than an older horse. Referring back to your goals and what you intend to do with your OTTB is an important consideration here. A past injury in a racehorse which may prevent it from high-level eventing may pose no issues for a horse intended for general pleasure riding.

Suboptimal hoof health is a common finding in the newly transitioning OTTB. This is often due to a combination of poor gastrointestinal (GIT) health (which influences nutrient absorption and the production of essential vitamins such as biotin needed for sound, healthy hooves). For more information on the role of GIT in overall health and the role of nutrition in hoof health see articles: Fibre, Chewing and Gastrointestinal Health; Ulcers in Horses: The importance of understanding how medications work; Hay, Stomach (Gastric) & Hindgut (Colonic) Ulcers; and Beyond Biotin: Optimising Horse Hoof Health.

Routinely being shod in race plates can also compound the problem of poor hoof structure and health. Many racehorses have contracted hooves with under-run heels, long toes and thin soles. Encouragingly, hoof health is an aspect that can readily be turned around in a period of around 8-12 months with appropriate dietary changes and good farriery. Including radiographs of the hooves as part of the pre-purchase examination may be a valuable investment in some horses: x-rays can help to demonstrate what is going on in the hoof and can aid the proactive farrier to trim, shoe and manage the hoof appropriately.

It is important to remember that often racehorses in training will initially go footsore when their shoes are removed and they are left barefoot during a spell. This is especially true of the front feet. Some farriers and owners will choose to keep their horses in shoes. In many cases however, it is advisable for the spelling horse to have an extended period of time being unshod: this helps to positively influence hoof shape and integrity and aids in proper circulation and blood flow to the hooves. Feeding the horse a diet which reduces inflammation, using nutritional supplements (nutraceuticals) and herbal medicine under qualified supervision, and potentially easing the transition to barefoot through the use of padded, removable boots are all beneficial strategies.

Another aspect of the pre-purchase examination should also include an upper airway scope. Respiratory conditions which may be evident when assessing an OTTB include a history of exercise-induced pulmonary haemorrhage (EIPH, more commonly known as bleeding), airway inflammatory disease, and laryngeal hemiplegia (roaring). The first two can generally be well managed with appropriate feeding and supplementation practices and adopting strategies to minimise the inhalation of air particulate matter and dust.

History

Where possible, finding out as much history about the horse as possible can help to make a smooth transition to the next phase of its career. For a horse coming straight off the track, contact with the trainer and/or stable manager can help provide you with valuable information as to any health or injury concerns with the horse, the dates it was last vaccinated and drenched (de-wormed), any medications and/or supplements it may have been receiving, its current diet and any quirks, habits or temperament considerations to take into account. Having said this, it is also important to remember that when a horse is put in a new environment, some of the aforementioned things may change! For example, a horse that was previously often irritable can become much calmer with a more natural diet and living environment. Similarly, horses which may have been very picky eaters whilst in training often become very good eaters once their GIT health has improved and the stress of the training environment has been removed.

Diet

The majority of diets fed to thoroughbreds in training are not conducive to optimal GIT health and function. Practices vary between trainers and stables, but most often, horses in training are fed two or three large grain and/or concentrate-based meals per day. Grass and/or lucerne hay are often provided in limited amounts. Many trainers do not have the luxury of turning horses out to graze. This puts the horse’s digestive system under strain and increases the likelihood of many health issues including ulceration throughout the GIT (gastric and colonic ulcers), colic, disturbances in the GIT microflora (bacterial balance of the digestive system), hindgut acidosis, suboptimal ability to utilise feed properly and nutritional deficiencies/insufficiencies. The addition of high cortisol levels produced by the horse in response to stress and high-intensity exercise further compromises GIT health and digestive function. To read more about the contributors and effects of stress in our horses see: Stress in Horses: Why it isn’t always obvious.

Horses, by nature, are designed to be constantly moving about and grazing high-fibre roughage. This is important as the stomach of the horse is relatively small in volume and has little capacity to expand. As a result, small amounts of feed which are consumed often are digested much better than the large volume feeds given a couple of times per day. The constant grazing a horse does in its natural environment also ensures that there is a physical buffer in the stomach to protect against the breakdown action of hydrochloric acid and digestive enzymes. These substances are constantly produced in the horse and are essential for proper digestion, as well as immune function. To read more, visit: Ulcers in Horses: The importance of understanding how medications work. Grazing and chewing also stimulate the production of saliva. Saliva serves many important functions in the horse, including releasing bicarbonate ions into the stomach (which also protects the stomach lining, another smart natural mechanism of the horse to protect against ulcers). To learn more about the benefits of grazing, visit: Why Basics Matter: The Importance of Chewing.

Sudden changes in feeding practices (even those that are beneficial to the horse) can increase the risk of colic and other complications. This is thought to be largely attributed to rapid changes in GIT microflora in response to the feed offered. Finding out the horse’s current diet prior to purchasing can help to make smooth transitions to a more fibre-rich feed, whilst ensuring the gut microflora change at an appropriate rate. It is advisable to make the transition of feeds gradual (over a period of 12-14 days) to help best facilitate this.

Whilst horses who come directly out of training will have been maintained on high-energy rations, their relative energy needs during their initial transition into an OTTB will be much lower. Furthermore, if GIT health is optimised as part of their transition (through feeding, management practices and appropriate supplementation), they will be better able to use fibre rich feeds (ie pasture and hay) as energy sources. This is made possible through bacterial fermentation in the hind gut (helpful microbes in the large intestine break fibre down into short-chain/volatile fatty acids, a high source of energy for the horse). It is important to remember that whilst a horse’s actual energy needs may be much lower than when they were in training, their need for specific minerals, vitamins and protein may remain relatively high. Without the excess demands of training and racing the body is in a prime position to help address and heal any niggling injuries, musculoskeletal damage or immune health challenges. To find out more about nutrient requirements and the role of protein for horses visit Nutrient Requirements for Horses: Fortified Feeds and the need for Supplementation; The Importance of Protein. These are commonplace in any athlete involved in demanding sports. To facilitate optimal healing and health, is essential to ensure that the OTTB receives at a minimum the recommended dietary intake of minerals and vitamins, in addition to good quality protein sources. A good quality balancer feed or supplement, in the addition to sufficient pasture, hay and lucerne hay (where appropriate) will help to meet these needs.

Some people find challenges in putting condition on their OTTB and/or the horse being picky with their feed. This is most often due to irritation of GIT, use of ulcer medications and non-steroidal anti-inflammatories (NSAIDs) such as ‘bute’ (PBZ), and the diet racehorses are commonly maintained on,. These factors can all significantly compromise gut integrity and health. Add to this the stress of a new environment and the change in the horse’s routine and it can take a little time for the horse to adjust. Whilst the prescription of appropriate nutritional and herbal supplementation can help immensely in these cases, basic management practices including turning the horse out to graze, the provision of sufficient roughage (hay, pasture), and keeping the OTTB  with a sensible paddock mate are all effective starting points owners are encouraged to implement. One of the most common mistakes that can be made when wanting to put weight on a newly acquired OTTB is to continually increase the ration of grain or high-energy concentrate feed, without the provision of sufficient roughage and fibre. This contributes to additional compromises in the integrity of the GIT lining and further shifting the hindgut microflora away from that which promotes the best utilisation of feed and energy. As a result, the cycle of struggling to gain weight is perpetuated, and often leads to frustration as the horse seems to take an extended period of time to ‘let down’ and gain condition. To read more about horse’s who struggle to put on condition, visit the article: HELP! My horse won’t put on body condition.

Down Time

One of the best things you can do as an owner of a newly transitioning OTTB is give it some much needed ‘down time’. The majority of racing stable environments are far removed from what is a natural for the horse. Like humans constantly under work deadlines, family demands and everyday pressures, horses too routinely experience stress. This stress is manifested in many forms, primarily driven by changes in levels of the stress hormone cortisol (which can lead to reduced immune function, high levels of inflammation, changes in temperament and behaviour, and reduced capacity to recover). Additionally, the constant physical demands of training and racing can lead to ongoing musculoskeletal ‘niggles’- aches, pains and minor injuries. A period of 4-8 weeks, turned out in the paddock, fed a fibre-rich diet, and not in the demands of work or being fussed with is one of the most beneficial things you can do to help the newly transitioned OTTB. It helps the horse to mentally wind-down, aids in the restoration of GIT health, gives any small niggles the chance to heal, and lets the horse settle into a new environment and freshen up. Just like humans, horses too need holidays. Simply giving them time out before asking new demands from them in their new career, can help them get off to the best start. 

Temperament

A significant (and often highly variable and unpredictable) consideration in the OTTB is temperament. This can be a challenge when acquiring a new horse, as it is difficult to know exactly how much is ingrained behaviour and the horse’s natural tendency, compared to how much it is a result of the environment the horse has been in, the feeding practices and GIT health. An important consideration to note is that 70-80% of the neurotransmitters (the chemicals which influence mood, temperament, behaviour and learning) are produced in the GIT. There are clear links between GIT health and levels of anxiety, mood changes and behaviour. This is useful to take into account: an OTTB which has struggled with compromised gut health in training and may be nervous, edgy or readily spook can change significantly when GIT health is addressed. A combination of appropriate supplementation and feeding, combined with appropriate ‘down time’ can really significantly impact the behaviour of an OTTB for the better. It routinely plays a role in why many horses that are temperamental/nervy/anxious in training become more relaxed away from the stable environment. Keep in mind too, that the actual environment the horse is kept in also plays an important role.

Monitoring and Progress

From a basic health standpoint, once the new OTTB has arrived and settled, it is wise to measure temperature, respiratory and heart rates at roughly the same time each day for a week to establish what is ‘normal’ for your horse. Record these and keep on hand (using the notes section on your mobile phone can be great, otherwise written on a whiteboard or somewhere easily accessible). This information is incredibly helpful in the instance that your horse may become unwell: you know what is ‘normal’ and healthy for your horse, helping to implement appropriate strategies in a timely fashion.

Taking photos of your horse from the side and back (safely), on a fortnightly or monthly basis is a simple tool to monitor body composition changes and progress. The same thing can be done with their hooves front and side-on, in addition to picking the hoof up and taking pictures of the sole and frog. It can be incredibly rewarding to look back over a 4-6 week period and notice the subtle improvement in body condition. Horses can make significant progress in gradual increments, which may be missed when you are seeing the horse on a daily basis. By having photo evidence on hand, you are able to make a more objective assessment. Keep in mind that changes in hoof shape and quality will be much slower to notice: front hooves take a full 8-12 months to grow from the coronary band to the toe.

The majority of horses in training are maintained on a routine drenching (deworming) schedule. Given our current state of understanding in relation to resistance to worming products, it makes sense to adopt a strategic drenching approach. In order to implement this safely and effectively, taking routine faecal samples to be sent off for testing are encouraged. Doing this at the commencement of ownership can help to provide guidance to the most effective drenching requirements of your horse. For more information on drenching/deworming visit the article Drenching/Deworming with Panacur.

Conclusion

Like most worthwhile things in life, effectively transitioning a racehorse to an accomplished OTTB takes time and patience! Knowing your capabilities as a rider and having clear goals as to what you want to achieve with your new mount are important starting points. Enlisting the expertise of suitably qualified professionals and equipping yourself with the knowledge of best practices can help make for a smooth and rewarding journey. Choosing an OTTB can make for one of the most gratifying experiences as a horse owner and rider. Careful consideration, planning and attention to detail can ensure you give your horse every chance to excel in its new phase of life.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

The cause(s) of IBD are not fully understood, however, it is thought that abnormal immune responses to bacterial, viral, parasitic, and/or dietary antigens play a key role. 

One such dietary allergen which has been highlighted is gluten, a protein which causes intestinal damage to people who suffer from coeliac disease. In recent years, gliadin (a component of gluten) has been reported to increase the permeability of the small intestinal mucosa and cause concurrent intestinal inflammation associated with IBD in the horse.

The key takeaway points from this are that diet can and does play an essential role in the health of the horse- beyond merely providing energy to fuel their work, growth and metabolic processes. 
As with any health condition in the horse (especially IBD), diet needs to be addressed for effective treatment/management of the condition in the horse. If the allergen remains in the diet, then inflammation and intestinal damage persists, despite treatment.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

The horse that fails to thrive can be one of the most frustrating challenges for owners, trainers, breeders and riders. The horse who no matter how much you feed it, how many times you drench (worm) it, how long it stays on medications for gastric ulcers or how many supplements you add to its feed- it still fails to put on significant weight, looks lacklustre and just doesn’t thrive like it should. Not to mention costing you an absolute fortune to keep! It’s common (and reasonable) to think that the more you feed the horse (particularly high energy grains and/or concentrates) the more weight and body condition it should gain. If a horse consumes excess calories (energy intake) relative to energy expenditure (calories out) then we would expect weight gain to occur.  And whilst the energy equation is an important consideration in such horses, if it was the sole reason in all cases, then horses that fail to thrive would be in the minority. The number of clinical cases where the primary reason for the owner contacting me is to help their horse gain weight suggests that this certainly is a common complaint. So why does it occur and what can we do to help these horses put on condition and thrive?

Potential contributors to failing to put on weight/condition

Like many health challenges and conditions in our equines, there are multiple factors which can contribute to failure to put on weight. Generally, it comes down to a combination of factors, not just one single reason. In the absence of a serious health condition in our horses, which should be ruled out by a thorough case history and veterinary diagnostics if indicated, the below are the most common reasons I see in clinical practice contributing to horses failing to thrive:

• Poor gastrointestinal (GI) health
• Insufficient fibre (particularly long-stem fibre in the diet)
• The volume of ‘individual hard feeds’ (ie grains and concentrates) too large per feed
• Horses being fed the wrong ‘type’ of feed
• Nutritional insufficiencies/deficiencies and imbalances (largely minerals and sometimes protein) which influence metabolic function (for example thyroid function)
• Side effects of certain medications (such as antibiotics, non-steroidal anti-inflammatories and corticosteroids)
• The use of gastric ulcer medications
• High stress levels in the horse
• High levels of pain in the horse
• High levels of inflammation in the horse
• Poor dental health
• High parasite load
• Inappropriate/insufficient exercise stimulus
• Windsucking/Cribbing

Poor Gastrointestinal Health

This is by far the most significant contributing factor relating to failing to put on/maintain weight in clinical cases I see. Poor gastrointestinal health can relate to compromised integrity of the cells lining the GI tract (gastric mucosa), imbalances in the microflora (the population of microbes, largely bacteria) of the GI tract and inflammation of the GI tract. These issues generally occur together. Gastric and/or colonic ulcers are also relevant in many cases, as a result of changes in the aforementioned factors. Many things can contribute to poor GI health (such as insufficient long-stem fibre in the diet, the use of certain medications- including ulcer medications, stress, travel, dehydration, just to name a few). To read more on these topics see articles:Hay, Stomach (Gastric) & Hindgut (Colonic) Ulcers; Hindgut (Colonic) Ulcers in Horses and Ponies; Inflammation & Non-Steroidal Anti-Inflammatories in Horses; Ulcers in Horses: The importance of understanding how medications work; Ulcer Medications: What Nobody Tells You and What You Need To Know; Fibre, Chewing and Gastrointestinal Health.

Insufficient Fibre

Sufficient dietary fibre is crucial in the diet of our horses’ and ponies’. In addition to promoting good GI health (see paragraph and articles above), fibre also serves as an important energy source in our horses. It’s easy to think that a horse who needs more condition needs more calories (the relative energy content of fibrous feeds such as hay is much lower compared to grains and most concentrates). Yet in addition to promoting healthy GI microflora, fibre serves as an important energy source for these microbes. They ferment the fibre to produce short chain fatty acids (SCFA) also known as volatile fatty acids (VFA). These fatty acids are a valuable ‘cool’ energy source for our horses, in addition to producing important anti-inflammatory compounds and promoting and maintaining a healthy GI tract. If we don’t feed our horses sufficient fibre, the lose out on these benefits. We can’t successfully ‘out-supplement’ insufficient fibre in our horse’s diets!

Volume (size) of ‘hard’ feeds

Horses have very small stomachs relative to the size of the animal, accounting for only 10% of the volume of the digestive system. Our horses are designed to be constantly ‘grazing’, which allows optimal digestive function. When our horses are fed large meals, which require relatively little chewing (such as grains and concentrates) the food passes through their stomach quickly. This results in the feed entering the small intestine largely undigested. Consequently, the horse isn’t able to extract the energy and nutrients from the feed properly, and the undigested feed enters the hind-gut, where it ferments and causes changes in the pH and microflora population. Whilst fibre passes largely undigested into the hindgut and is naturally fermented here (and provides significant benefits because of this), no other feed should be fermented in the hindgut. In a mature horse, individual meal sizes should be no more than 2.3kg (5 pounds) in volume.

Horses being fed the wrong ‘type’ of feed

Feeding horses a commercial pelleted or mixed concentrate feed can be an efficient way to help meet nutrient requirements. However, not all pelleted or commercially manufactured feeds are created equally. They vary vastly in ingredients contained, nutrient and energy content. Feeds on the market range from low calorie mineral balancers to high energy concentrates. Feeding a low calorie balancer (even in large quantities) won’t significantly contribute to energy intake in our horses. Hence, selecting an appropriate feed is really important to help the horse failing to thrive.

Feeding large amounts of hard-to digest grains or concentrates is also a common occurrence in the horse failing to thrive. On paper it can make logical sense to feed the lightly conditioned horse plenty of grains as they are generally high in calories. Yet these grains aren’t always readily digested, and feed that isn’t digested properly won’t help to condition our horses well. For example corn (even cracked/rolled corn), despite being relatively high in starch and calories has very poor digestibility. This means our horses are not able to efficiently utilise the calories in it, in addition to it also adversely effecting GI microflora, compounding the whole problem. Remember that many high calorie concentrate/manufactured feeds contain large amounts of grains.

Nutritional insufficiencies, deficiencies and imbalances

In addition to sufficient energy (calories), our horses need protein (made up of amino acids), fats, vitamins and minerals to serve multiple different functions in the body. Sufficient protein is needed to aid in muscle hypertrophy (growth) thus plays an important structural role in conditioning horses. Additionally, the amino acids found in protein are needed for the production and activity of digestive enzymes. Digestive enzymes help our horses to properly break down their feed, allowing for the absorption of energy and nutrients. Along with fats, vitamins and minerals, protein also plays key roles in supporting metabolic function and the production of key hormones needed to promote healthy growth in our horses. Insufficiencies or relative imbalances in these key nutrients can both directly and indirectly affect a horse’s ability to put on body condition.

Side effects of certain medications

Particular medications commonly used in our horses have the ability to impact their body condition. Antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone (bute) and flunixin (Banamine), and corticosteroids all impact a horse’s GI microflora and the integrity of their stomach lining. Lesser considered medications include omeprazole and ranitidine (the key active ingredients in most ulcer medications), which interfere with a horse’s ability to properly digest and absorb their feed, and also impact their GI microflora. Other medications such as diuretics (Furosemide/Lasix) influence the absorption, metabolism and/or excretion of key nutrients needed for healthy metabolic function and conditioning in a horse. Medications such as Clenbuterol (Airway Gel, Claire Gel) and synthetic thyroid hormone (L-Thyro) directly influence metabolic rate in a horse, commonly resulting in weight loss or inability to put on sufficient condition.

The use of gastric ulcer medications

It can seem quite ironic- medications commonly used to help aid in healing of gastric ulcers can actually compound the challenge of gaining condition in the poor doer. Gastric ulcer medications work by shutting down the production of hydrochloric acid. Yet without adequate hydrochloric acid our horses can’t properly digest, absorb and metabolise their feed and nutrients in it. As a result, feed passes largely undigested in to the hindgut, adversely impacting GI microflora. To learn more about the actions of ulcer medications, visit the articles: Ulcers in Horses: The importance of understanding how medications work; Ulcer Medications: What Nobody Tells You and What You Need To Know

High stress levels and/or high levels of pain

High and/or continued levels of stress and/or pain in our horses results in changes in the production of the hormone cortisol and chemicals which promote inflammation in the body. This in turn commonly results in the breakdown of muscle tissue, leading to difficulty putting on/maintaining condition- largely lean muscle mass (the kind of condition we want on our horses). Changes in GI blood flow and microflora balance also commonly occur as a result of stress, further impacting digestion. Additionally gastric and/or colonic ulcers, which frequently develop as a result of chronic stress, can further compound the problem. To read more on the systemic effects of injury and pain, see the article: Injury and Pain in our Horses and Ponies

High Levels of inflammation

Long-term (chronic) inflammation in horses reduces the synthesis of muscle protein. It also increases the rate at which muscle proteins break down. Special types of molecules called inflammatory cytokines, which are  involved in cell signalling during inflammation, trigger the release of cortisol and particular neurotransmitters (chemical messengers in the body). The combination of cortisol and these neurotransmitters disrupt cellular metabolism and alter a horse’s metabolic rate, which can heighten the breakdown of muscle tissue.

Poor dental health

Dental health can influence a horse’s ability to put on and/or maintain body condition in several ways. Sharp edges on teeth, loosened teeth, tooth infections, tooth loss or uneven wear of teeth can contribute to pain and compromised ability to chew feed well. Properly chewing feed is an important part of initiating digestion in the horse, allowing it to adequately utilise feed.

Less commonly considered aspects of dental health in our horses are gingivitis (gum inflammation) and periodontitis (where the inner layer of the gum and bone pull away from the teeth and cause pockets of air between the gums and teeth). These conditions affect horses in a similar way to humans. Gingivitis usually precedes periodontitis and begins when bacteria in the mouth proliferate around the teeth and gums. The build-up of large numbers of bacteria that attack the gingiva or gums leads to inflammation. It’s important to note that as the disease progresses and the gums become swollen and bleed, bacteria are able to enter a horse’s bloodstream and travel around the body. This can result in high levels of systemic inflammation and adverse changes to gut microflora, thereby influencing overall health and digestive function. To read more on the systemic effects of dental health in horses, visit: Bad Breath in Horses

High parasite (worm) load

Did you know that there are more than 150 types of parasites that affect horses? The four most common types are strongyles, ascarids, tapeworms and bots. High numbers of parasites (a high parasite load) can contribute to inflammation throughout our horses’ digestive tracts, damage to the lining of the stomach and intestines and gastric and/or colonic ulcers. These inhibit our horses’ ability to properly digest and absorb their feed.

Simply drenching/worming our horses more frequently is generally not the answer. This can contribute to increased parasite resistance to anthelmintics (drugs used to help kill parasite), in addition to impacting a horse’s GIT microflora. Best practices involves the use of appropriately timed faecal egg counts, assessing parasite burden in the horse, and strategic drenching using appropriate anthelmintics. For more information on best drenching/deworming practice visit: Drenching/Deworming with Panacur

Inappropriate/insufficient exercise stimulus

For our horses to develop and maintain muscle mass and body condition there are several important components. Good GI health to properly digest, absorb and metabolise nutrients needed for protein synthesis and muscle cell growth (hypertrophy) are essential. Our horses also need to be fed a diet which meets both their protein and calorie requirements. An easily overlooked factor is appropriate type and quantity of exercise. Our horse need to be engaging the correct muscles in the correct frame to develop good muscle growth and conditioning. Horses who are not exercised adequately, and/or not engaging the correct muscles when working will fail to capitalise on their ability to develop good muscle mass. Horses who are spelling, injured or on box/stall rest will likely not maintain their best muscle mass. A useful analogy can be to think of a person who wants to gain muscle mass or muscle definition. If they eat plenty of protein and calories, yet spend their day largely inactive, sitting on the couch and not exercising, they will fail to properly develop optimal muscle strength and definition. On the other end of the spectrum, someone who trains really hard in the gym, but fails to eat enough quality food to fuel their training will not maximise muscle development gains. It takes a combination of both training and proper fuelling! To read more, visit: What Supplements are best for building Topline?

Windsucking/Cribbing

Windsucking (also known as cribbing or crib-biting) in horses is a stereotypy, or repetitive behaviour which can significantly impact a horse’s ability to put on or maintain weight.

In addition to weight loss and overall poor condition, wind sucking can result in abnormal development of muscles in the neck, and excessive wear of teeth- affecting a horse’s ability to chew properly. Cribbing can interrupt a horse’s daily routine, occupying several hours per day. This reduces time spent grazing and foraging. Cribbing is commonly associated with digestive discomfort, gastric ulcers and imbalances in specific neurotransmitters- all factors which are known to influence a horse’s ability to properly digest, absorb and metabolise their feed. To read more about windsucking/cribbing visit: Why do horses wind suck and crib bite?

The horse who fails to gain or maintain adequate weight and muscle mass can be frustrating. Whilst it is common to look at one likely reason for their weight struggles, there are generally several factors contributing to the state of the horse’s health. The good news is that when contributing factors are properly identified and addressed, the horse who once had difficulty putting on and/or maintaining weight can flourish. Additionally, by correcting the underlying issues, you are helping to facilitate the best health and performance in your horse.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

From a dietary perspective, it is thought that horses may chew wood when they aren’t consuming enough fibre in their diet. This can happen to horses who are kept in stables or in paddocks. It’s common to think that horses who are grazing pasture are consuming enough fibre to meet their needs, but grass is relatively low in fibre. Unless sufficient hay is fed in addition to grass, horses will likely fall well short of their fibre requirements. Adequate fibre in the diet is incredibly important for optimal gastrointestinal (GI) function, promoting balanced microbial flora of the GI tract, preventing ulcers, supporting immune function and supporting neurotransmitter production (just to name a few of its roles!). To read more about the importance of fibre for horses and ponies visit the articles: Hay, Stomach (Gastric) & Hindgut (Colonic) Ulcers; Fibre, Chewing and Gastrointestinal Health; Why Basics Matter: The Importance of Chewing.

Lignophagia may also be due to boredom (which again, can commonly arise due to not enough grazing). Left unaddressed, chewing wood may develop into a stereotypy behaviour. As with any abnormal behaviour it should be viewed in a holistic context.

Other reasons for a horse to chew wood may be due to poor GI health- particularly imbalances in the microflora population of the digestive tract. This is commonly associated again with insufficient fibre in the diet (although there are many other factors which may also contribute). Specific micronutrient insufficiencies/deficiencies may also play a part in lignophagia. Weather conditions can play a role in the habit in some horses, with research showing that horses are more likely to gnaw on wood during wet, cold weather. This may be due to an instinctive urge for more roughage in their diet as temperatures fall.

Identifying and addressing the reasons why a horse is chewing wood is important, as the behaviour comes with its own set of health risks in our horses and ponies. Chewing wood places unnecessary wear on a horse’s front teeth, which can make chewing less effective and hinder digestion. They may also ingest sharp wood fragments, which can injure your horse’s digestive system. In rare cases, they may also lead to the formation of enteroliths (intestinal stones that form within the colon and can obstruct the intestine, resulting in colic).

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

In many cases, the source of pain in our horses can be diagnosed and attributed to a specific injury or degenerative process such as osteoarthritis. Yet the pain itself rarely occurs in isolation. Other physiological changes occur which influence the sensations our horses experience and their perception of pain.

In the case of acute injury in our horses (think muscle, tendon or ligament damage) there is associated inflammation and commonly oedema (swelling). There are also changes in the types and balances of neurotransmitters produced (chemicals which influence temperament, mood, behaviour and pain perception) and alterations in cortisol levels. These initial changes occur to help the body facilitate healing of the damaged tissue- and to a certain extent are desirable and necessary.

When injury or inflammation becomes prolonged however, the body’s responses become dysregulated. What started out as a normal healing response becomes dysfunctional and can lead to chronic pain and tissue degeneration. Further alterations in neurotransmitter production and function occur- resulting in heightened pain perception in our horses. There is often a concurrent increased production of neurotransmitters associated with anxiety: think of the horse in pain who is always on edge. The anxiety experienced with chronic pain can lead to the experience of greater pain intensity: physiologic changes within the neurological system cause a phenomenon of central sensitisation to pain. Furthermore, stress and anxiety can promote the release of pro-inflammatory mediators, which cause further damage to tissue and more pain.

Contrastingly, it is common to see horses in chronic pain who experience depression. These are the horses which become withdrawn. The ones who you can look at their eye and know they are not ok. As a result of chronic pain, neural pathways in the brain change. Even when tissue damage is resolved, our horses can still experience real pain. The use of NSAIDs cannot help with this.

In the case of injuries- particularly those that are long-standing, horses can ‘guard’ the painful area, hold excessive tension in muscle, fascia and other tissues and change their biomechanics and movement patterns to cope with the pain. Appropriate body work and rehabilitation exercises are an important part of an integrated approach to help facilitate healing and prevent further compensation or injury moving forward.

Pain and inflammation may contribute to certain nutritional deficiencies and/or insufficiencies in our horses and ponies. This is particularly true of chronic pain. Both excesses and insufficiencies of specific nutrients can also increase pain perception and inflammation and are a key consideration to address.

Whilst providing appropriate pain relief is absolutely paramount when indicated, it is important to remember that in many cases, the use of anti-inflammatories alone will not adequately address all the causes of the pain. We also need to be aware of the changes these drugs make to the integrity of the gastrointestinal tract and associated microflora, which in turn influence inflammation, pain perception and systemic health (to read more see articles: Inflammation & Non-Steroidal Anti-Inflammatories in Horses; Anti-Inflammatory Drugs and Recovery). 

Effectively helping horses or ponies in pain, particularly long-standing or chronic pain should encompass a multi-faceted approach. Addressing neural pathway involvement should be a primary consideration, in addition to identifying and rectifying imbalances in specific neurotransmitters. Appropriately prescribed herbal medicines and nutraceuticals can help to facilitate this. The role of nutrition in the equine suffering from pain is also important: ensuring that no nutritional excesses, deficiencies, or insufficiencies are increasing their pain experience. Where appropriate, body work and rehabilitation exercises should also be incorporated. Unless the causes of pain are properly addressed, our horses will potentially continue to go through the cycles of discomfort. Understanding how and why the pain has occurred is important to help effectively treat and resolve it.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

What we know from current research is that simply giving our horses tryptophan as a supplement doesn’t help promote calm behaviour- in fact, it may do the very opposite. Low doses of tryptophan given to horses actually promotes excitement, whilst high doses have been shown to reduce endurance capacity and cause haemolytic anaemia. In either case, hardly helping with overall health and performance.

The reasons for the effects of tryptophan supplementation on horses are likely multifaceted. We know that responses to tryptophan are species dependent- whilst it can be helpful in humans and some animal species, the same cannot be said for horses.

It is important to remember that very few nutrients act in isolation. For tryptophan to be converted to serotonin, it has to go through several metabolic processes. Each of these processes requires key nutrients to facilitate the conversion. Without sufficient nutrient levels and good gastrointestinal health to facilitate this, the conversion and metabolism of tryptophan are effected.

We also need to remember, like many facets of health- there is a sweet spot between not too little and not too much. The same is true for serotonin- too little, and our horses can be anxious, too much and they can become agitated.

The take-home message is that whilst some supplements can be incredibly useful, not all are. We can better promote healthy neurotransmitter levels (such as serotonin) by ensuring our horses are receiving a balanced diet providing all key nutrients in appropriate quantities and forms. Additionally, we want to ensure that we’re promoting optimal gastrointestinal health, as this in turn helps to facilitate both healthy nutrient production and neurotransmitter levels.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Horses and ponies are able to synthesise (make) their own vitamin B12 when they have a healthy balance of hindgut microflora, sufficient fibre in their diet and a suitable mineral intake- particularly adequate dietary cobalt.

What is commonly overlooked is the fact that injectable vitamin B12 is rapidly and nearly completely excreted via bile into a horse’s manure. In essence- they can’t use or absorb this form of B12…it just makes for expensive poo!

Having a healthy digestive system is incredibly important in our horses and ponies to promote many facets of their health: good hoof quality and growth, optimal metabolic and immune function, the production of neurotransmitters (natural chemicals) which help to promote calm behaviour and reducing inflammation.

The production of optimal levels of vitamin B12 to aid in athletic performance are just another reason why we need to focus on sound feeding and management practices and the judicious use of medications in order to promote good gastrointestinal and overall health. It is also an important reminder that we often just can’t out supplement poor dietary practices.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

In many cases, a non-steroidal anti-inflammatory drug (NSAID) such as phenylbutazone (bute/PBZ) is used with the belief that it may help our horses. Other NSAIDs that may be used include flunixin (Banamine), meloxicam, aspirin or firocoxib.

When our horses undertake hard exercise, micro damage occurs in connective tissue (bones, muscles, tendons, ligaments). This micro damage is normal and is an important part of how our horses get stronger, fitter and adapt to training. Natural prostaglandins (special hormone-like compounds produced by the horse’s body) are produced in response to exercise and help to promote blood flow and to heal connective tissue after exercise. These prostaglandins play a key role in inflammation. We tend to think of inflammation as ‘harmful’ and excessive inflammation can negatively impact our horse’s health. There is a happy medium, however, and our horses need a certain amount of inflammation, particularly post-exercise to promote healing and recovery. When our horses are given NSAIDs, the production of these important prostaglandins is inhibited, in turn reducing our horse’s normal healing capacity and adaptation to training.

Furthermore, we know that the use of NSAIDs has adverse effects on gastrointestinal (GI) health. These drugs can cause damage to both the lining of the stomach and intestines, contribute to ulcers (both stomach and colonic) and cause undesirable changes in GI microflora (to read more, visit Inflammation & Non-Steroidal Anti-Inflammatories in Horses). The effects of NSAIDs on GI health can further compromise recovery and adaptation to exercise in addition to the direct effects of impaired prostaglandin synthesis.

Whilst excessive levels of inflammation in horses can contribute to poor health, a certain amount of natural inflammation, particularly post-exercise is absolutely key to optimal recovery and improving fitness and strength.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

THE HOW:
The importance of fibre (particularly long-stem fibre, such as that found in hay), cannot be underrated in the prevention of not only stomach (gastric) ulcers but also hindgut (colonic) ulcers.

One of the main mechanisms by which hay helps to protect the gastric mucosa is by providing a physical barrier between the cells lining the stomach and the acidic contents of the stomach. This barrier protects the stomach lining from direct exposure to hydrochloric acid.

The other main mechanism is through the production of saliva. Hay requires plenty of chewing. The more a horse chews, the more saliva it produces. Saliva contains bicarbonate ions, which help provide a chemical buffer to protect stomach mucosal tissue.

In terms of preventing hindgut/colonic ulcers, the protective mechanisms differ from gastric ulcers- but are incredibly important. Fibre passes through a horse’s stomach and small intestines undigested, where it reaches the large intestines. Here it undergoes bacterial fermentation by specialised microbes (note- it is normal and healthy for horses to digest fibre in their hindgut, it is NOT healthy for them to ferment undigested grains and other feedstuffs in their hindgut). The fermentation of the fibre results in the production of substrates known as short-chain fatty acids (SCFAs) or volatile fatty acids (VFAs). There are several kinds of SCFAs, one of great importance being butyrate.

Butyrate is used as the main energy source for cells of the colon (colonocytes) and is needed for them to maintain a healthy colonic barrier. Butyrate also helps to inhibit pathogenic (‘bad’) bacteria from adhering to and damaging the lining of the colon. Colonic ulcers arise from an inflamed or damaged colonic barrier- therefore the action of butyrate is protective against these.

We tend to think of hay as a ‘filler’ feed for horses and ponies and something that we need to restrict in fat ponies and something that is not overly helpful in the horse who is lacking condition. It can also be easy to overly focus on the ‘hard feed’ we give our horses and ponies and not think too much about hay. Whilst hay and long-stem fibre is certainly not the only thing needed for good gastrointestinal (GI) health, it is certainly very difficult (if not impossible) to have good GI health without sufficient hay (or an appropriate alternative source of fibre).

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

The signs and symptoms of both gastric and colonic ulcers can be very similar, and both can be very general and non specific. In the case of gastric ulcers, vets are able to perform a gastroscope to confirm (or exclude) the presence and severity of ulcers. Unfortunately, the tools available to diagnose hindgut ulcers are limited and don’t necessarily give us the same definitive answers.

Something that is really important to be aware of is that when colonic ulcers are suspected and stomach ulcers have been ruled out, the use of ‘ulcer medications’ (oral medications containing the active ingredient omeprazole or ranitidine and injectable esomeprazole) are NOT indicated. Ulcer medications stop or significantly reduce the production of hydrochloric acid in the stomach. These medications may actually contribute to worsening of the problem through interfering with proper digestion and causing more undigested feed (which should begin digestion in the stomach both directly and indirectly through the action of hydrochloric acid) to enter the hindgut and ferment. The only thing that should ferment in the hindgut is fibre! Other feeds fermented in the hindgut can contribute significantly to inflammation, damage to cells lining the hindgut and adversely impact delicate balances of microflora.  Hydrochloric acid is NOT produced in the hindgut and does NOT contribute to hindgut ulcers.

It’s worth remembering that both gastric and colonic ulcers can exist concurrently, and that simply ruling out gastric ulcers as a cause of a horse’s signs and symptoms doesn’t necessarily mean that their gastrointestinal (GI) health is good. The successful treatment of gastric and/or hindgut ulcers should involve a comprehensive dietary and management plan (both during the healing phase and long-term), and identify and address the factors which have contributed to the development of poor GI health in the effected horse.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

The horse or pony prone to laminitis can be a challenge to keep healthy. Poorly managed or severe episodes of laminitis can lead to devastating consequences. Diligence and modification to the diet and management regime of a horse or pony at risk of or with laminitis are required to prevent further deterioration or episodes of the condition and keep the equine in the best health possible. If a supplement on the market claimed to prevent acute episodes of feed related laminitis AND didn’t require changes in the way we feed and manage our horses and ponies, then surely that would be great? On the surface, maybe, but when we understand about HOW such a product possibly prevents laminitis and the potential long-term health repercussions, then stopping to reconsider its use is certainly warranted. Especially when one of the leading equine veterinary authorities in the world completely ban its use.

One widely promoted and used product on the market contains the active ingredient Virginiamycin. Virginiamycin is an ANTIBIOTIC.

It is well known, researched and demonstrated that antibiotics have an adverse impact on gut health through several mechanisms. They kill off not only ‘bad’ but ‘good’ bacteria which play many essential roles in our horses’ and ponies’ digestive systems. Amongst other functions, these healthful bacteria help to break down the fibre in hay and roughage to produce ‘cool’ energy for our horses; they produce substances which play a role in preserving the lining of the gastrointestinal tract (GIT) helping to reduce inflammation and protect against ulceration; they produce B group vitamins, biotin and vitamin K- essential for energy production, hoof health, reproductive health, bone health and strength, and recovery from exercise to name a few; they are intimately involved in the production of neurotransmitters (chemical messengers which influence our horses’ moods, temperament, behaviour, gut motility, etc); and these helpful bacteria also play a crucial role in proper and healthy immune function. Furthermore, compositions of specific ‘good’ GIT microflora have been shown to play an important role in metabolism, blood glucose control and insulin sensitivity: all which may have a protective effect in the horse or pony at risk of insulin resistance (IR) and equine metabolic syndrome (EMS). It is well known that horses with IR and/or EMS are at an increased risk of laminitis.

Antibiotics are also known to increase intestinal paracellular permeability and promote intestinal barrier dysfunction- sometimes referred to as ‘leaky gut’. Episodes of laminitis are commonly a sequelae of the above.

Through the use of antibiotics, bacteria (both ‘good’ and ‘bad’) are kept in check (although with increasing antibiotic use and levels of antimicrobial resistance eliminating the ‘bad’ bacteria is becoming increasingly more difficult) thereby keeping some of the triggering factors to laminitis episodes at bay.

We KNOW that diet has a significant influence in the majority of cases of laminitis. We also know that the integrity of the GIT lining also plays a paramount role. In horses with poor digestive health (which is common and can be caused by many factors- visit the Articles section on Optim Equine’s website to read more) high grain/carbohydrate diets have been shown to change bacterial populations (to non-favourable bacteria) in the hindgut. These bacteria produce lactic acid through fermentation, damaging the GIT lining and contributing to a cascade of events that can result in laminitis. In theory, as long as the horse is kept on this antibiotic, rapid shifts in gut microflora which may precede laminitis are less likely to occur. Therefore helping to ‘prevent’ it.

There are a few issues with this. The constant use of antibiotics actually impairs the integrity of the gut lining through several mechanisms. One of the many supportive roles of ‘healthy’ bacteria are to protect and promote a healthy GIT lining. Part of this mechanism involves reducing intestinal inflammation.

Secondly, when a horse comes off the ‘supplement’ (medication) unless strategic dietary practices are implemented, the microflora balance will more likely default to an unhealthy one as a consequence of the use of antibiotics…thereby actually further increasing their risk of future episodes of laminitis than before they were on the supplement in the first place. Keep in mind too that antibiotics also degrade the protective barrier function of the intestinal lining. 

Then we’ve got the nutritional consequences as a result in shifts in GIT microflora. Horses on antibiotics are now lacking the beneficial bacteria to help them properly digest and utilise fibre as an energy source, in addition to the myriad of roles those healthy bacteria play in overall health and performance as outlined previously.

Virginiamycin has been completely banned for animal use in the UK since 2014. This alone should ring alarm bells! The antibiotic was banned as it posed a risk to increased development of antimicrobial resistance. The Veterinary Medicines Directorate (VMD) also found no robust evidence that Founderguard prevents laminitis. They supported that this condition can be managed though animal husbandry and pasture management. They declared the use of Founderguard in horses no longer justified. Globally, we need to recognise the very real problem of antimicrobial resistance and responsible prescribing of antimicrobials in the veterinary profession. As the pathology which drives laminitis is not caused by bacterial infection, we must ask ourselves is the use of antibiotics in this instance responsible? 

We have the opportunity to support healthy GIT microflora, promote healthy GIT integrity and feed our horses so they are able to perform at their best and be in the best of overall health and help prevent laminitis. This is largely dependent not only what we feed our horses, but how we feed them too. It also involves looking at the way we use routine medications in our horses and incorporating alternative strategies to minimise unnecessary use and addressing the side effects they cause when they are required…

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

The smell of our horse’s breath isn’t something we generally give much thought to. Yet if you’ve ever smelt the breath of a horse or pony with halitosis (bad breath)- then it becomes something hard to ignore. So why do some horses and ponies have bad breath and is it something to be concerned about?

Many factors can contribute to bad breath in the horse or pony: the most common being bacterial overgrowth in the mouth, decreased saliva, dental plaque, periodontal disease, cracked teeth and tooth abscesses. Yet the causes of bad breath aren’t just limited to the mouth alone. Infection in the respiratory tract and poor digestion can all contribute to bad breath. The side effects of some medications may also contribute to halitosis.

Oral Contributors

Halitosis can arise due to a lack of saliva production. The major salivary gland in our horses, the parotid gland, only secretes saliva when a horse chews. When our horses or ponies go long periods of time without grazing or consuming fibrous feeds such as hay, there are significant periods of time when there is little saliva in the mouth. The horse fed one or two concentrated/hard feeds daily, with little hay or grazing in between producing much less saliva than nature intended them to. Saliva has a multitude of functions in relation to our horse’s health, one of these being important antimicrobial activity through naturally occurring antibodies it contains. Lack of saliva production due to lack of chewing creates the perfect breeding ground for high levels of specific bacteria to build up in our horses’ mouths. This results in malodour. The effect is compounded by feeds that are high in sugar and/or starch, which can further ‘feed’ these ‘bad’ bacteria.  Furthermore, a dry mouth and lack of chewing fibrous feeds can also contribute to increased volumes of plaque on the teeth, giving rise to bad breath. Saliva helps rinse away tiny particles of food debris that may otherwise settle on the teeth and cause dental plaque. For more information on saliva and the importance of chewing in our horses visit the article: Why Basics Matter: The Importance of Chewing.

Gingivitis (gum inflammation) and periodontitis (where the inner layer of the gum and bone pull away from the teeth and cause pockets of air between the gums and teeth) affect horses in a similar way to humans. Gingivitis usually precedes periodontitis and begins when bacteria in the mouth proliferate around the teeth and gums. The build-up of large numbers of bacteria that attack the gingiva or gums leads to inflammation and malodour. It’s important to note that as the disease progresses and the gums become swollen and bleed, bacteria are able to enter a horse’s bloodstream and travel around the body. The effects of periodontal disease extend far beyond the mouth: it may be associated with reproductive problems in our horses and other undesirable conditions. Gum disease can contribute to loosened teeth, tooth loss and infections in the bone surrounding the teeth.

Poor Digestive Function

Hydrochloric acid (HCl) is an essential component of healthy digestion in our horses and ponies. It is produced by specialised cells in the stomach called parietal cells. One of the many functions of HCl is to help keep bad bacteria and opportunistic micro-organisms in check. When HCl production is reduced or shut down (as is the case with the use of ulcer medications) a perfect environment is created for opportunistic bacteria to flourish (for more information on the way ulcer medications work and their effects, visit the article: Ulcers in Horses: The importance of understanding how medications work). These bacteria produce compounds that result in a foul odour. Another crucial role of HCl is facilitating proper digestion and breakdown of food. Without sufficient HCl to help initiate normal digestion and maintain an acidic pH in the stomach, feed can ferment in the gut- resulting in the production of malodorous gasses. For these reasons, bad breath can be an indication to look at digestive health beyond the mouth. 

Medication Side Effects

A wide variety of medications commonly used in horses and ponies may contribute to halitosis through differing mechanisms. Some antibiotics, anti-fungals, anti-histamines, diuretics, sedatives, bisphosphonates and dimethylsulfoxide (DMSO) may all cause or contribute to bad breath in equines.

Respiratory Tract Infections

Sinusitis (inflammation of the lining of one or more of the sinuses) and upper respiratory tract infections can also contribute to bad breath in our horses. These are generally accompanied by mucoid (whitish, yellowish) nasal discharge out of one or both nostrils. Clinical signs may also include swelling or bulging of the facial bones, decreased appetite, lethargy and weight loss.

Nutritional Deficiencies/Insufficiencies

Beyond the type of feed our horses consume and how frequently they are fed, many key nutrients play important roles in oral health. Insufficiencies and/or deficiencies in protein, vitamin A, vitamin D, zinc and impaired production of B group vitamins and vitamin C may all be implicated in compromised oral health, leading to bad breath.

Conclusion

There are many causes and contributing factors to bad breath in horses and ponies. Whilst poor dental and oral health are obvious cases of bad breath, diet, medications, gastrointestinal and respiratory system function may all play important roles. Foul smelling odours from the nostrils and/or mouth warrant further investigation by suitably qualified professionals. Properly identifying and addressing the cause(s) of halitosis help to promote overall health in your horse or pony, as well as helping them to have a non-offensive smelling breath!

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Digestion literally begins in our horse’s mouth- both from a mechanical (chewing) and enzymatic (chemical) perspective. Our horses grasp their food with their lips, tongue and teeth. The structure of their jaw allows for a complex chewing motion: the upper jaw being wider than the lower jaw. Horse’s chew in a sweeping action (lateral, forward, backward and vertical motions), which aids in both the mechanical breakdown of food, in addition to mixing food with saliva. Amylase is an enzyme contained in saliva which helps chemically begin the digestion of carbohydrates. Unlike humans, horses only produce saliva in response to chewing. The more they chew, the more saliva they produce. This is really important to note- as in addition to facilitating enzymatic digestion in the mouth, saliva contains bicarbonate ions. These bicarbonate ions act as buffers to help protect the stomach lining against naturally produced hydrochloric acid (essential for healthy digestion, but corrosive to the stomach lining). This is one of the many natural mechanisms a horse has in order to help maintain a healthy gut lining (protecting against ulcers and gastrointestinal inflammation).

The jaw sweeps (chewing rate) of a horse are influenced by the type of feed they consume. On average, a horse at pasture makes 60,000 jaw sweeps per day when grazing. This is dramatically reduced when a horse is confined to a stable and/or roughage in the diet is limited, with concentrates/grain forming a large part of their diet.

On average, a 500kg horse takes around 40 minutes and 3400 jaw sweeps to consume 1kg hay. By stark comparison, 1kg of oats only takes 10 minutes and 850 jaw sweeps to consume. One of the most concerning consequences of this dramatic decrease in chewing rate is a significant reduction in bicarb production (thus minimising a key protective mechanism of the gut lining).

When a horse chews fibrous feeds it uses a long jaw sweep action. Horses maintained continually on pasture with minimal grain rarely develop sharp edges on their teeth as their natural chewing mechanism maintains even wear. When horses chew grains they use a shorter sweeping action, which doesn’t extend past the outer edge of their teeth. A diet high in concentrates or grain and low in fibre is an important contributing factor to the development of sharp edges on our horse’s teeth. Poor teeth wear can set up a vicious cycle- a horse in pain from sharp edges on their teeth typically reduces their chewing rate of fibrous feeds, thereby further contributing to poor gut health due to less fibre consumption and less bicarbonate production.

There are MULTIPLE reasons why roughage should comprise a significant part of your horse’s diet. Their effects on dental health and the initial stages of digestion alone are important aspects highlighting the need for sufficient fibre in the diet.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

What is Protein?

Protein is a crucial macronutrient in a horse’s diet and is comprised of long chains of building blocks called amino acids. There are 21 amino acids. The specific order and combination of amino acids determines the structure and function of each protein. Insufficient dietary intake of specific amino acids limits the production of key proteins essential in our horse’s bodies. For more in-depth information on protein quality see the article: Soy: The Good, Bad and Confusing.

Protein is Needed for Growth, Maintenance and Repair of Tissue

We commonly only think of this as important when we are trying to increase muscle mass in a horse. For instance, building top-line on our ridden horse, or conditioning a thoroughbred yearling for sale. Yet protein is absolutely essential for normal growth and development of the young horse, and recovery from riding and training in active horses. Insufficient protein in the diet can therefore increase risk of illness and injury in our horses. Times of illness and injury also increase protein requirements in order to help recover from the illness or heal from the injury. Providing insufficient protein to a sick or injured horse during their recovery can significantly delay and/or impair their healing and adversely impact their future athletic potential.

Protein Facilitates Biochemical Reactions

Enzymes are a specific type of protein that aid in the normal biochemical reactions that take place in a horse. Specific enzymes are needed to facilitate proper digestion (therefore helping to promote optimal gut health and utilisation of feed); energy production (helping a horse to perform); normal metabolism (helping to regulate weight and temperature in a horse); blood clotting; and muscle contraction. Insufficient protein in the diet can lead to digestive problems- a critical consideration given the heightened focus on gastrointestinal (GI) health. A common mistake is to restrict protein intake in the overweight horse: this can further slow metabolism (compounding the problem) and compromise overall health.

Protein is Required for Proper Communication in the Body

Hormones are chemical messengers that aid in communication between a horse’s cells, tissues and organs. They are needed for everything from normal growth, metabolism, reproductive function and digestion. Amino acids are also an important component of neurotransmitters: the chemical messengers which play a crucial role in a horse’s mood, temperament, learning and behaviour.

Protein Provides Structure

Different types of protein are essential for the formation of healthy bones, tendons, ligaments, muscles, skin and hooves. Depending on the type of protein, they aid in providing structure, strength, elasticity and rigidity to specific tissues. Insufficient protein in the diet can make a horse more susceptible to injury to muscles, tendons, bones and ligaments. They may also have poor skin and/or hoof quality.

Protein Helps to Maintain pH Balance in the Body

Proteins act as a buffer system, helping a horse’s body to maintain proper pH values of the blood and other bodily fluids.

Protein Helps to Balance Body Fluid Levels

Albumin and globulin are two important proteins found in a horse’s blood. They help to maintain the body’s fluid balance by attracting and retaining water. If a horse’s diet has consistently has low quantities of quality protein, the levels of albumin and globulin eventually decrease. This can result in swelling or oedema as these proteins can no longer keep blood in the blood vessels, forcing the fluid into the spaces between cells. The irony is that protein is often blamed for causing swelling in horses- with the reverse often being the cause!

Protein is Needed for a Healthy Immune System

Protein is absolutely essential for white blood cell production and the formation of immunoglobulins (antibodies) needed to fight infection in our horses. Insufficient protein in the diet can leave a horse more susceptible to bacterial, viral and fungal infections.

Protein Aids in the Transportation and Storage of Nutrients

Transport proteins carry substances in our horse’s blood streams- into, out of and within cells. The substances transported by these proteins include nutrients such as vitamins and minerals, blood sugar, cholesterol and oxygen. Whilst we often think of iron as being a key driver in helping oxygen delivery to the body’s tissues, protein plays a paramount role- yet is often overlooked. Specific proteins also have a storage role: ferritin is a storage protein that stores iron.

Problems with Excessive Protein: Myths or Facts?

So now we can see that protein is absolutely vital in keeping our horses healthy, yet is there a downside to this nutrient? And can we feed too much? Like most things, the answer is relative to the situation and the individual horse.

Excess Protein

To overly simplify, horses are unable to store excess protein that they consume in their diet for later use. The metabolism of excess protein increases levels of nitrogen end-products, such as ammonia and urea. A diet containing excess protein will increase the horse’s water requirements and urine output as the ammonia and urea are flushed out of the body. If a horse is kept out at pasture, is only in light work and has free access to plenty of fresh water, this generally isn’t a problem. It is an issue however where horses are stabled. Exposure to this strong urine can cause lung irritation and other respiratory problems. Extra urination means extra wet bedding, which equates to more mucking out.

Metabolism of Protein Produces Heat

Protein digestion and metabolism is a heat generating process. A horse that is on a high protein diet that is burning a lot of protein as an energy source will sweat more to help get rid of the heat. It is important to remember that the body has a preference for using carbohydrates and fats over protein as an energy source, and will only use protein as a significant energy source when these other two nutrients don’t meet their requirements. Protein fed in appropriate amounts to meet a horse’s needs will not contribute greatly to heat production or sweating. Feeding excessive amounts of protein however, particularly to horses in hot and humid climates, or those undertaking moderate to heavy work, can contribute to dehydration and heat stress.

Protein Causes Poor Behaviour/ Hot Horses: MYTH

Protein is often blamed for making horses ‘hot’, nervy or spooky. This is turn can cause some owners to avoid including quality sources of protein in their horse’s diet. Protein has not been shown to cause behavioural issues in horses. Diets which are high in energy and excessive to a horse’s energy needs which are also high in protein can contribute to a horse being hyperactive or silly. The problem here is the overall energy intake, not the protein!

Kidney and/or Liver Damage: MYTH

In healthy horses, high protein diets have not been demonstrated to cause kidney and/or liver damage. In horses that have pre-existing liver or kidney problems, then protein intake may need to be restricted- ensuring that intake is still sufficient to meet a horse’s daily requirements but does not exceed them.

Take Home Message

As a general rule, I see far more horses in clinical practice with insufficient protein intakes compared to those with excessive protein intakes. Insufficient protein in the diet may leave a horse more susceptible to illness and/or injury and delay or impair their recovery. Including adequate, quality protein in the diets of our horses is absolutely essential in order for them to be healthy, perform and recover at their best.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Many horses spend the majority of their days in small paddocks, yards and stables. They only need to move minimally to have access to feed and water. Essentially, they are quite idle. Although widely variable depending on discipline, many horses in hard work don’t do more than 1-2 hours most days. Ridden time aside, they are essentially quite idle.

This is in stark contrast to the way horses move in herds in nature. Natural social groups of horses have evolved to never stop moving or eating for very long. Research in semi-feral herds has shown that horses move at least 17km per day! At different periods throughout the year, the distance they cover can increase significantly. When in search of forage or when interacting with other herds, horses may move up to 160km daily.

This movement plays a crucial role in keeping horses healthy. Contrastingly, lack of physical movement in domestic horses is an important contributing factor in many health conditions we see today. The large volumes of physical activity (along with the diet of wild horses) helps to prevent horses being overweight. The physical activity improves insulin sensitivity an important factor in metabolic syndrome, as well as many cases of laminitis. Laminitis in our horses is largely a ‘man-made’ disease.

The constant physical activity increases bone density and strength, as well as promoting muscle, tendon and ligament strength and development. This is likely to lead to stronger, sounder horses.

So how can we implement some of these benefits in our man-made modern settings?

We can take some of the principles and incorporate them into the management of our horses. The suggestions listed below are general suggestions which can be used where they are possible, safe and feasible. It’s about making the best of the situation and facilities that you have.

Where possible:

• Choose keeping your horse turned outside in preference to stabling.
• Choose larger fields over smaller paddocks and yards.
• Choose turning out in mobs as opposed to turnout alone to encourage movement and interaction.
• Consider the implementation of natural track systems in paddocks to encourage movement.
• Feed well away from water source- ie water at one end of the paddock, feed at the other.
• Consider hand walking the horse that isn’t ridden frequently.

For the majority of horses and ponies, increasing their overall daily physical movement and activity is most beneficial. Small changes can have a significant positive impact on your horse’s health, soundness and longevity.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

As a prey species that graze open plains: horses evolved to be slow to show discomfort. Being hard-wired not to show pain is a survival mechanism to protect their livelihood. This is especially true in situations where they feel threatened, as this significantly risks their survival.

Almost any physical discomfort in the horse can result in behavioural changes. Commonly these include things such as kicking, stomping, pawing, biting, teeth grinding, head-tossing, or self-mutilation at work or rest. These can be confusing for us as people to experience or observe, as often the horse doesn’t appear to be in discomfort.

So how do you know if the behaviour is because of pain?

Undertaking a thorough physical assessment of the horse, reviewing dietary intake, medication use, management practices and farriery practices are all sound places to start. For the horse who exhibits such behaviours only when riding, saddle and bit fit should also be assessed.

A useful strategy is to video the horse without anyone present (ie set up a camera in the stable/stall, yard or paddock) to see if it’s doing more conspicuous discomfort behaviours.

Poor behaviour rarely occurs without reason. Identifying and addressing the drivers of poor behaviour is important for the welfare of our horses, and the safety and enjoyment around equines.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Heat stress occurs when a horse’s thermoregulatory system cannot adequately dissipate heat. It is most common when exercising in hot, humid conditions, as exercise results in the generation of heat. Heat dissipation relies on evaporation of sweat: sweat cools the skin down and the blood flowing through it by evaporation. In hot, dry air, sweat evaporates very quickly but as the humidity increases, the speed at which sweat evaporates becomes less effective. Overweight and/or unfit horses are less effective at dissipating heat, increasing their risk of heat stress.

As a horse’s sweat levels increase, so does their loss of essential electrolytes. Horses are able to sweat faster than any other animal (thereby helping to cool themselves). Additionally, the electrolyte content of horse sweat is highly concentrated. The most significant electrolyte lost in sweat is salt. Salt must be supplemented in the horse’s diet to meet their daily sodium requirements- this is true even when horses sweat minimally. Processed horse feeds do not contain sufficient salt for basic daily requirements. Grass, hay and other feeds also do not help to meet our horse’s salt requirements. If electrolytes aren’t adequately replaced in the diet, insufficiencies/deficiencies and imbalances in electrolytes can occur in our horses (horses cannot make their own electrolytes). These imbalances and deficiencies in turn increase the likelihood and/or severity of poor performance. They may also be implicated in exertional rhabdomyolysis (tying up) and synchronous diaphragmatic flutter (thumps).

Dehydration is a risk factor in many horses. As they can sweat at such high rates, fluid losses are accentuated. Dehydration can increase the risk of several health conditions, one of the most common being colic. Dehydration can slow the passage of food material in the gastrointestinal (GI) system and make faeces much drier and firmer- resulting in impaction colic.

Respiratory health complications can also arise from dehydration. Respiratory tract irritation, inflammation and infection may all be consequences of dehydration. In a dehydrated horse, the mucus in the airways of the lungs increases in viscosity (thickness) and moves slower- resulting in accumulation of matter in the lungs.

Hot and/or humid weather can cause horse feed to go off much quicker than usual and can change the nutritional content of processed feeds. High fat feeds and oils will quickly go rancid in hot weather (it is important to note that this can occur without the feed or oil smelling ‘off’). This can lead to a horse consuming less feed than normal. Dehydration can also result in reduced appetite.

Some minerals and vitamins in different feeds also deteriorate in quality with heat, further compounding health issues. Reduced feed intake and/or changes in metabolic rate associated with hot and humid environmental conditions, can lead to weight loss in the horse.

Signs and symptoms to look out for that may be indicative of detrimental effects of heat and/or humidity in the horse include:

• Increased rectal temperature
• Poor performance
• Poor recovery post exercise
• Panting (fast, shallow breathing)
• Blowing excessively for a prolonged period of time after exercise
• Lethargy (often accompanied by the appearance of being unsteady on their feet)
• Muscle spasms
• Feeling very hot to touch
• Dark and/or reduced urine
• Nostril flaring
• Decreased appetite and/or thirst
• Irregular heart beat
• Thumps (synchronous diaphragmatic flutter)
• Dark mucous membranes
• Very prominent blood vessels on the skin

Helping to prevent heat stress and/or the consequences of high temperature and humidity takes a multi-faceted approach. Heat acclimatisation (when important competitions/events take place in the heat) is an important consideration. Horses, like humans, can become acclimated to heat. This generally takes 2-3 weeks, and requires them to be sensibly exercised in the heat and/or humidity on a daily basis. It is important to take into account that even fit, well acclimated horses may experience reduced performance in hot and/or humid weather conditions. Quite contrastingly- if you enjoy riding during hot weather (but are not competing in events that take place in the heat) then exercising your horse in the coolest parts of the day is an effective strategy.

Post exercise, adequately cooling down and hosing off your horse is important. In cases where a horse is extremely hot, hosing for 10-15 minutes with cold water may be necessary. Its best not to scrape the water off your horse in this case: water which sits on the skin will evaporate and help to contribute to the cooling process.

Ensure clean drinking water is always provided to your horse and don’t withhold water before or after exercise. Offering water immediately after exercising is recommended, as this is the time when a horse’s thirst is strongest. Try to avoid ice cold water, but don’t restrict intake. Giving water to a healthy horse post exercise is not associated with causing colic. With increased sweating rates, horses have increased fluid requirements- so expect and allow them to drink more.

The daily provision of adequate salt and the appropriate use of electrolytes are important to help maintain normal physiological processes in the body.

Exercising horses in hot and/or humid weather can pose some challenges, but sensible management and riding practices can help to minimise these. Keeping our horses properly hydrated, cooling them effectively post exercise, and ensuring we meet their dietary requirements are important factors in keeping them healthy in hot, humid weather.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Problems start to occur when levels of inflammation are excessive, and/or occur for extended periods of time- beyond that which the body needs for normal healthy repair and functioning. Inhibiting the body’s own repair and defence mechanisms however, can also be problematic.

Non-steroidal anti-inflammatories (NSAIDs) are one of the most widely used classes of drugs in horses. The most commonly used NSAIDs in equines include phenylbutazone (bute), flunixin meglumine (commonly sold under brand names including Banamine, Finadyne, Flu-Nix, Flunixamine), firocoxib (Equioxx, Previcox) and meloxicam (Metacam).

How do Non- Steroidal Anti-Inflammatories Work?

When it comes to using NSAIDs in horses and ponies, understanding how these drugs work can help to make an informed approach about their appropriate use.

Non-steroidal anti-inflammatory drugs work on a chemical level. They inhibit the effects of special enzymes: specifically cyclooxygenase (COX)-1 and COX-2 enzymes. These enzymes play a key role in making prostaglandins which promote inflammation. By blocking the COX enzymes, NSAIDs reduce the production of prostaglandins and in turn inflammation. It is important to remember that other inflammatory pathways exist in the horse: COX-1 and COX- 2 are most commonly targeted.

COX-1 is expressed in nearly all tissues in the horse’s body and is necessary for proper gastrointestinal (GI) function, renal (kidney) function, and blood coagulation. COX-2 is also expressed at low levels in many tissues, contributing to normal kidney function and interestingly, playing a critical role in the healing of the gastrointestinal (GI) mucosa (cells lining the GI).

The potential risks

Most people are well aware of the deleterious effects the use of NSAIDs can have on the GI lining in our horses. Although ulcers commonly come to mind, the effects of these drugs on the digestive tract of our horses extend far beyond this. In the case of phenylbutazone and flunixin, the production of mucin (which is one of our horse’s internal mechanisms for protecting and maintaining a healthy gut lining) is stopped. This is the primary way in which damage to the GI (including the development of ulcers) can occur with NSAID use. It is critical to note that this occurs regardless of whether the NSAID is given orally or by intravenous (IV) injection. It is not the physical presence of the drug in the GI system that causes the damage, it is the changes in inflammatory pathways.

It is common practice to give ulcer medications (specifically those containing omeprazole) in conjunction with NSAIDs, with the belief that this may help to offset the detrimental effects to the GI. Research has demonstrated however, that this practice can further compound damage caused to the GI mucosa. This is likely due to changes in blood flow to the gut lining and shifts in protective microflora of the GI.

Changes to GI microflora associated with NSAID use is a lesser discussed but equally important aspect in terms of our horse’s health. Although beyond the scope of this article, specific microflora serve crucial protective and anti-inflammatory actions in the GI of our horses. Significant changes in these fine balances of microflora can occur in association with NSAID use. This in turn has significant implications on the nutritional status of our horses. To read further on this topic visit the Gastrointestinal (Gut) Health heading in ‘Article’ section of the Optim Equine website.

Research has also indicated that the use of NSAIDs following hard work, competition or training is likely to inhibit desired adaptations and proper recovery to the exercise undertaken. Changes in blood flow and cellular repair mechanisms vital for proper recovery are altered by the use of NSAIDs. The practice of giving NSAIDs as a precautionary or ‘preventative’ method after hard work, racing, competition or training may in fact work against what is trying to be achieved.

What about selective and preferential COX-2 inhibitors?

In more recent years, the use of NSAIDs that selectively or preferentially inhibit COX-2 and don’t (in theory) inhibit COX-1 may cause fewer adverse effects than nonselective NSAIDs. Examples of these drugs include firocoxib and meloxicam.

Selective COX-2 inhibitors don’t entirely spare COX-1. They also inhibit COX-1 to a small degree, but generally carry a lower risk for direct damage to the gut lining. An interesting point to note is although COX-2 selective drugs may decrease the risk of developing GI ulcers compared to non-selective NSAIDs, they can impair the healing of pre-existing ulcers.  Additionally, similar to non-selective NSAIDs, COX-2 inhibitors are associated with changes in gut microflora, which in turn can lead to adverse effects on the GI system.

It is important to note that COX-2 is involved in normal, healthy kidney and cardiovascular function (thus administration of selective COX-2 inhibitors can still cause adverse renal and hameodynamic effects in susceptible horses).

The dosage amounts of COX-2 inhibitors needs to be taken into account when evaluating their potential risks and side effects. When COX-2 inhibitors are used in higher doses, their ability to be selective in their action on COX-2 enzymes decreases. That is, higher doses may cause effects similar to those of nonselective NSAIDs. Combining NSAIDs (for example, administering firocoxib and phenylbutazone together) has also been shown to increase the risk for adverse effects, including that to the kidneys.

Takeaways

Non-steroidal anti-inflammatories have their place in illness and injury in horses and like all drugs, their use should be judicious. Selective and preferential COX-2 inhibitors may have less adverse effects on the GI system than non-selective NSAIDs, but still come with risks. Appropriate dietary, nutraceutical and supplementation practices may help to decrease detrimental effects to the GI, cardiovascular system and kidneys associated with NSAID use. Employing specific therapeutics and dietary strategies to restore gut mucosal integrity and reinstate a healthy GI microflora following NSAID use is highly advisable. In low and appropriate doses, selective COX 2 inhibitors may be a better choice in reducing adverse side effects when NSAID use is necessitated

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

Managing energy intake is certainly a critical strategy in successfully preventing and/or managing these conditions in our horses. It’s important to remember that there are numerous other highly influential factors on body weight, body composition and metabolism. These include exercise and activity levels, various hormonal levels, the effects of specific medications a horse may be on, and specific vitamin, mineral and other nutrient levels.

One of the most fascinating, yet less appreciated influences on a horse’s metabolic rate and body composition are the types and balances of bacteria that reside in their hindgut. Specific types of bacteria in a horse’s hind gut produce short chain fatty acids (SCFAs) also known as volatile fatty acids (VFAs) through a process of fermentation. Short chain fatty acids help to reduce the development and accumulation of fat cells, promote the breakdown of fats and reduce pro-inflammatory cytokines (thereby reducing inflammation). Short chain fatty acids may help to reduce body weight and improve insulin sensitivity- extremely important factors in managing the overweight horse and preventing further complications.

These bacteria need plenty of fibre to survive and thrive. This is one of the many reasons why starvation diets for overweight horses are not suitable. Severely restricting an overweight horse’s fibre intake often compounds the metabolic problems.

In order to successfully manage the overweight horse or pony (or prevent at risk equines from becoming overweight) we need to address all the contributing factors which influence their metabolism. Whilst energy (feed) intake is one of these components, the type of feed is just as important. Appropriately addressing activity levels, specific nutritional components and promoting optimal hindgut microflora are paramount.

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

It is well understood that performance and racehorses are subject to significant amounts of stress. This stress in and of itself can result in sub-optimal or poor performance in our horses. Performance aside, prolonged stress has a myriad of flow on effects to the overall health of our horses: it can compromise the wellbeing and function of the gastrointestinal system, the immune system, and the production and function of neurotransmitters (the brain chemicals influencing temperament and behaviour).

What is easily forgotten is that stress affecting our horse’s performance and well being does not necessarily have to originate from sources associated with training or the competitive event. Read that sentence again.

Performance and racehorses are exposed to a range of stressors most of which relate to the way they are kept, fed and managed (this is largely dictated by training regimes, available facilities or convenience). These are stressful because they affect the behavioural needs of the horse as a species.

Behavioural needs are species-specific highly motivated behaviours that are performed by an animal and more often than not have a functional role. The horse has some physiological ‘need’ to perform the behaviour. Foraging (grazing) is a primary example of this. In a natural environment, forage is generally available ad lib with a horse spending up to 70% of its day eating! For horses, the reduction of eating time to two meals per day can meet the nutritional requirements of the animal, but is unlikely to meet the horse’s behavioural need to forage. In the competition horse, restriction of behavioural needs induces a chronic stress response which will subsequently prevent optimal individual performance. It also has a significant flow on effect to gastrointestinal (gut) and immune health.

Some of the most basic feeding and management practices have the most profound influence on our horse’s health and performance. It can be easy to rush in and add the latest fad supplement to our horse’s feed to try and remedy a stressed horse or poorly performing horse, but it is more valuable to ask ourselves:

• What are some of the less obvious sources of stress in our horses?
• What are some of the dietary and management changes we can make for true lasting benefit?

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.

For the purpose of this article, we will focus on soy bean meal and feeds containing processed soy- not soy oil or soy bean hulls- as these components alone have significantly different nutritional value and properties.

Pros

Soy is one of the more widely fed significant sources of protein in a horse’s diet. It is a common misconception that protein is only needed to promote weight gain, muscle condition or the development of topline. Whilst it is important in these instances (in combination with appropriate exercise and training), protein is absolutely essential for a multitude of functions in all horses at any life stage and exercise level: it is a critical component of normal immune function; facilitates proper growth and repair of the musculoskeletal system; and is needed for the majority of metabolic processes in the horse. Even horse’s who aren’t in heavy work and/or actually need to lose weight need sufficient protein in their diet.

Protein is comprised of smaller units called amino acids. Horses require 21 amino acids, 12 of which a horse can synthesise (produce) themselves. The remaining nine (and in the case of illness or injury- potentially ten) amino acids must be present in a horse’s diet. These are known as ‘essential amino acids’. In addition to all essential amino acids being present in the diet, they must be present in appropriate quantities- so a horse has enough of each of them to facilitate various bodily functions. If they fall short of any essential amino acids then health, normal development, performance and recovery may be compromised.

With the exception of oils, practically all horse feeds, grains and forages contain SOME protein- Depending on the exact feed source, the actual amounts of protein contained in these feeds will vary. Different sources of protein are comprised of different sequences of amino acids. This influences how useful they are to a horse. Some high protein feed sources are actually of little value to a horse, as they lack decent amounts of essential amino acids that a horse needs, or they are unable to be properly digested and absorbed by a horse.

So how does all this relate to soy? Soy is one of the best dietary sources of lysine for our horses and ponies. Lysine is a very important essential amino acid in the equine and it is generally one which is lowest in our horse’s diets. Lysine is absolutely essential for normal muscle growth and turnover, helps to promote collagen integrity (important for healthy bones, skin, muscles, tendons and ligaments), is critical for proper immune function, and may further help bone health through improving calcium absorption and utilisation. Animal studies have also shown that diets low in lysine may be associated with anxiety. Thus, a diet low in lysine may be one of many potential contributing factors in some cases of horses with an anxious tendency.

For horses competing in endurance events, optimising hydration pre-event is an important consideration. Commercial soy feed products which require soaking before being fed, can help to increase fluid intake in horses. It’s important to keep in mind that there are other feeds which can be used for this same purpose. Soy is not the only option.

Being a low starch and protein rich feed, processed soy meal can aid in stabilising blood glucose levels- thus helping to prevent rapid spikes in insulin levels. High insulin levels are a driving factor of equine metabolic syndrome and are commonly implicated in many cases of laminitis. Horses with Pituitary Pars Intermedia Dysfunction (PPID) (also commonly referred to as ‘Cushings’) and Polysaccharide Storage Myopathy (PSSM)- a component in many cases of ‘tying up’, may also particularly benefit from a diet low in starch and containing adequate quantities of quality protein.

The phytoestrogen content of soy is an important, yet often misunderstood concept. Soy is unique in that it contains a high concentration of isoflavones, a type of plant oestrogen (phytoestrogen) that is similar in function to the hormone oestrogen but with much weaker effects. Soy isoflavones can bind to oestrogen receptors in the body and can either increase or decrease oestrogen levels in the body. Research has demonstrated that when oestrogen levels in the body are naturally low, then ingestion of phytoestrogens may help to increase the body’s levels.  When oestrogen levels in the body are naturally high, then consuming phytoestrogens may help to reduce oestrogen levels, as they bind to some of the receptor sites that naturally produced oestrogen may bind to.

Potential Cons

The phytoestrogen activity of soy may also potentially be a drawback of this feed. Excessively high intakes of phytoestrogens have the potential to decrease testosterone levels, an important consideration in stallions and colts. Soy certainly isn’t the only source of phytoestrogens commonly found in horse diets: clover grass is rich in phytoestrogens. Before attributing potential positive or negative effects of phytoestrogens in a horse’s diet, the total quantity of all phytoestrogen rich food sources needs to be taken into account.

Soy is commonly attributed to causing allergic symptoms in horses- everything from itchiness and skin irritation, colic and digestive disturbances, to overly-reactive behaviour and respiratory issues. Whilst soy is a common allergen in humans, the same has not yet been demonstrated in horses. Diagnostic tests for equine food allergies are difficult to carry out, time-consuming and often unreliable. In clinical practice, I find that the majority of horses with allergy related symptoms (whether these be environmental or food related) improve significantly when overall nutritional status and specific components of both immune and gut health have been therapeutically addressed. Generally something which may appear to cause allergic symptoms in a horse is not the real culprit.

A significant valid concern with soy is the fact that it is one of the most commonly genetically modified (GM) crops. Whilst this is only an issue in some parts of the world, it is certainly worth taking into consideration. Animal studies with GM foods indicate that they may cause some common toxic effects such as hepatic, pancreatic, renal, or reproductive effects and may alter blood parameters and immune function.

Soy is high in omega six fatty acids. Whilst these types of fatty acids are an essential component in our horse’s diets, they are generally present in higher than desirable amounts. Of further importance is the percentage of omega six fatty acids in proportion to omega three fatty acids. High levels of omega six fatty acids with accompanying low levels of omega three fatty acids are known to promote inflammation. Adding large amounts of soy products to a diet already high in omega six fatty acids further accentuates the shift towards a pro-inflammatory tendency. This can  have wide-ranging effects from impairing recovery from training, competition and exercise; compromising immune function; and exacerbating already existing inflammatory conditions such as osteoarthritis, desmitis, placentitis and laminitis to name a few.

Uncooked or even inadequately cooked soybean meal has some anti-nutritional factors. Trypsin inhibitor is the most significant one. Trypsin is an essential enzyme which helps horses to properly digest protein, allowing for absorption and metabolism of the amino acids which make up the protein. Trypsin inhibitor found in uncooked soybean prevents trypsin from being able to properly break down proteins. This means that in the presence of trypsin inhibitors a large percentage of all protein from all sources a horse is consuming is unable to be properly digested, absorbed and metabolised.

Some concerns exist that soy can have a negative effect on thyroid function and can alter the levels of thyroid hormones. Whilst the majority of data is from human studies, it is unlikely that regular consumption of small amounts of soy containing foods have significant impact on thyroid function in healthy subjects. In cases where hypothyroidism already exists (keeping in mind that diagnosis and true cases of hypothyroidism in horses is rare), then reviewing the appropriate feeding of soybean containing products is warranted.

Conclusion

Processed soybean meal and feeds containing this product can be a valuable inclusion in the diets of many horses. Factors which may caution against the feeding of soy to some horses include specific health concerns and where in the world the soy is grown and produced. Soybean meal MUST be properly heat treated to prevent trypsin inhibitor from interfering with protein digestion. The quantity of soy products fed and the overall diet of the horse are crucial factors to take into consideration.

Rarely is anything inherently good or bad: the same may be said of soybean products. The most important consideration is that one size doesn’t fit all: feed the individual horse in front of you!

Optim Equine

Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.

As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.