Recognizing the Signs of Pain in Horses
By: Shannon J. Murray, DVM, MS, DACVS-LA | Updated May 22, 2025
Pain is a complex, physical and emotional experience that can be challenging to treat in animals. In simple terms, pain is an unpleasant experience caused by injury or even the threat of harm to the body. Pain is not only physical, but also involves emotional responses like stress, fear, and discomfort. This can make pain hard to recognize and sometimes harder to treat.
How Horses Process and Feel Pain
Pain pathways—also known as nociception—in horses work much like they do in humans and other animals. This is a complex system of signals and responses that help horses detect and react to injury or other harmful stimuli.
Specialized nerve endings called nociceptors are located all over a horse's body. They act like sensors that pick up signals from painful stimuli. When a horse experiences something painful, like a cut or internal injury, these “sensors” are triggered and send electrical signals along the nerves to the spinal cord. The spinal cord acts like a highway for these signals, carrying them up toward the brain, where they are processed and perceived as pain.
The brain’s interpretation of these signals causes the horse to react—such as moving away from the source of pain or shifting weight off a sore leg. These behavioral changes are often the first visible signs of discomfort.
As a horse owner, being able to identify and alleviate your horse’s pain is critical. You know your horse best and can often detect the subtle signs that indicate discomfort. Should you have any concern that your horse might be in pain, it is important to work with your veterinarian to come up with a plan to help diagnose the cause and determine appropriate treatment.
Types of Pain Horses Can Experience
Horses can experience several types of pain, depending on the source and duration of the discomfort:
- Acute Pain: Involves activation of nociceptors and occurs immediately after injury when withdrawal from the harmful stimulus fails to prevent tissue damage. This can lead to inflammatory pain as part of the healing process.
- Inflammatory Pain: Occurs because of the body's natural response to injury or infection and can involve swelling, redness, or heat in the affected area. The pain usually lasts as long as the inflammation is active.
- Chronic Pain: Pain that persists after the injury has healed. This pain response is considered maladaptive, meaning it no longer serves a protective function. Instead, it reduces the horse’s quality of life. A common example of chronic pain in horses is laminitis, which may also involve neuropathic pain components.
- Somatic Pain: Linked to stimulation of nociceptors in the skin, muscles, joints, bones, or connective tissues. It can be superficial (from a wound or skin irritation) or deep (such as from a muscle strain or a fracture).
- Visceral Pain: Originates from the internal organs—such as the gastrointestinal tract, lungs, or bladder. In horses, colic is a classic example of visceral pain.
- Neuropathic Pain: Caused by damage or dysfunction in the peripheral or central nervous systems and is considered maladaptive. A condition in horses considered to be associated with neuropathic pain is headshaking (trigeminal nerve neuropathy).
How to Recognize the Signs of Pain in Horses
Since horses are not able to verbally tell us what is wrong, it’s crucial we observe both their behavioral and physical signs. Horses in pain will often begin showing more abnormal behaviors, which could include (but are not limited to):
- Repeatedly rolling or attempting to lie down
- Kicking at their abdomen
- Turning to or watching their flank
- Pawing
- Non-weightbearing lame, shifting weight or lifting a specific limb, abnormal gait, or a reluctance to move
- Loss of or decreased appetite
- Repeated stretching
- Attempting to urinate unsuccessfully
- Curling upper lip (flehmen response)
- Weight-shifting or lifting a specific limb
- Vocalization
- Restlessness
- Standing at the back of their stall or away from the herd in pasture
- Holding their head low below the height of the withers
- Muscle tremors
- Sweating
- Tail swishing (for no apparent reason)
- Teeth grinding
- Laying down more than usual
- Quiet, dull, or less interactive
- A change from normal attitude or energy level
- Weight loss
- Ears held back
- Eyelid partially or completely closed
- Tension above their eyes
- Increased tension of the muscles around their mouth
- Flared nostrils
Changes in heart rate and respiratory rate can also be indicators of pain, although these may also result from other factors such as stress or exercise. Therefore, physiological changes should be considered alongside behavioral signs and diagnostics.
Developing an Equine Pain Scale
Steps are being taken to create a comprehensive, reliable, and objective pain scales for horses. The Equine Expression Pain Scale shows promise in experimental studies validating facial features consistently associated with severity of pain. However, further research is needed regarding a universally accepted pain scale for horses.
When in Doubt, Call Your Veterinarian
If you have any concerns that your horse could be in pain, you should never hesitate to contact your veterinarian. Once it has been established that your horse is experiencing pain and its cause, your veterinarian can help guide you in a plan for pain management.
Evidence-Based References
- Daglish, Jodie, and Khursheed R Mama. “Pain: Its Diagnosis and Management in the Rehabilitation of Horses.” The Veterinary clinics of North America. Equine practice vol. 32,1 (2016): 13-29. doi:10.1016/j.cveq.2015.12.005
- van Loon, J P A M, and M C Van Dierendonck. “Objective pain assessment in horses (2014-2018).” Veterinary journal (London, England : 1997) vol. 242 (2018): 1-7. doi:10.1016/j.tvjl.2018.10.001
- Muir, William W. “Pain: mechanisms and management in horses.” The Veterinary clinics of North America. Equine practice vol. 26,3 (2010): 467-80. doi:10.1016/j.cveq.2010.07.008
- Love, EJ. “Equine Pain Management”. Equine Surgery. Auer and Stick. 263-268.
- Guedes, Alonso. “Pain Management in Horses.” The Veterinary clinics of North America. Equine practice vol. 33,1 (2017): 181-211. doi:10.1016/j.cveq.2016.11.006
- de Grauw, J C, and J P A M van Loon. “Systematic pain assessment in horses.” Veterinary journal (London, England : 1997) vol. 209 (2016): 14-22. doi:10.1016/j.tvjl.2015.07.030