Horses, Ponies and Pain

Pain can be one of the most heartbreaking things to watch our horse or pony experience, particularly when we can’t accurately identify the source of and provide relief from the pain. Many different types of pain exist, which means that effectively identifying, managing and treating the source of pain should be tailored to the individual horse or pony in front of us.

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 If the pain is chronic/ongoing, the horse or pony may become withdrawn or ‘shut down’ in order to manage their pain.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.