Teaching a Horse to Stand Still at the Mounting Block
Horses can show their pain in many, sometimes subtle, ways. | Anne M. Eberhardt/The Horse

Lameness, characterized by asymmetrical movement patterns, is the main cause of poor performance in equine athletes. “The annual incidence of lameness is nine to 14 cases per every 100 horses and 50% to 67% of athletic horse operations report at least one horse with lameness at any given time,” said Elizabeth Davidson, DVM, Dipl. ACVS, ACVSMR, associate professor of sports medicine at the University of Pennsylvania’s New Bolton Center, in Kennett Square, during her lecture at the 2024 Dressage at Devon, held Sept. 24-29. Horses in pain can also present with abnormal behaviors such as bucking, difficulty performing a select movement, or falling behind the vertical, so it is important to regularly assess your horse’s behavior to ensure he is not experiencing pain.

Equine Lameness and Behavior Evaluations

If you notice an abnormality in your horse’s behavior or movement patterns, work with your veterinarian to determine the root cause. Your veterinarian will likely perform a physical examination, in-hand evaluation, and might observe the horse under saddle if needed, said Davidson. These evaluations could include palpation, watching the horse walk and trot in a straight line and in a circle, and flexion tests. She added that a ridden gait evaluation can enhance the veterinarian’s observation of the following in horses with less obvious lameness:

  • various gaits and their quality
  • variable speeds within the gaits
  • specific movements (i.e., leg yield or shoulder-in)
  • horse-rider interaction

During a ridden examination, your veterinarian can also evaluate dangerous behaviors, such as bucking or rearing, or any other undesirable ridden behaviors such as lack of impulsion, falling behind the vertical (the front of the horse’s nose falls behind a vertical line dropped from the top of its forehead when viewed in profile), or resistance to the rider, which could indicate pain, said Davidson.

The facial pain scale, called the horse grimace scale, can help owners and veterinarians decipher more subtle signs of pain, such as ears back, open mouth, or flared nostrils in an objective way. Authors of the scientifically validated ridden horse pain ethogram describe common horse pain behaviors in detail to help owners and veterinarians determine their significance. “These behaviors are 10 times more likely to be seen in lame horses than nonlame horses,” said Davidson.

Diagnosing Lameness in Horses

Your veterinarian will apply diagnostics, such as nerve blocks or imaging, based on abnormalities observed during the evaluation. Veterinarians perform nerve or joint blocks by putting a small amount of anesthetic into the structure to numb it. This can help reveal if pain in that area is the cause of the horse’s pain or undesirable behavior. “We want to avoid finding abnormalities in the wrong part of the horse’s body,” said Davidson. “We want to make sure what we’re finding is the reason for the lameness.”

If a horse’s clinical signs are inconsistent (not reliably reproducible) or dangerous to observe in a traditional lameness evaluation, your veterinarian might choose another method of observing the horse to make a diagnosis. “This could include a neurologic evaluation with a specialist, 24-hour video monitoring, a bone scan (which can highlight areas of bone injury), or ruling out systemic pain (such as gastrointestinal problems),” said Davidson.

Take-Home Message

Regularly observe your horse both on the ground and under saddle and make note of any abnormal behaviors that might indicate pain in your horse. If you notice lameness in your horse, even to a small degree, work with your veterinarian to determine the cause and develop a treatment or rehabilitation plan. “There is value in localizing a horse’s pain,” said Davidson. “This can help us focus our diagnostics and imaging to ensure we find the true cause of the horse’s pain and can create a specialized treatment plan.”