While diagnostic imaging technology and treatments for equine back pain have improved in recent years, the clinical examination remains a vital part of accurately diagnosing and treating spinal problems in horses. “Ninety-four percent of ridden horses experience back pain,” said Sandro Colla, DVM, MS, postdoctoral fellow at Colorado State University’s College of Veterinary Medicine & Biomedical Sciences, in Fort Collins. Colla explained the role of the clinical examination and functional assessment in diagnosing back problems in horses during his presentation at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida.
Equine Back Anatomy and Biomechanics
The horse’s back includes fascia, muscles, tendons, ligaments, and bones, which work together to support the horse as he moves and works. The fascia is a layer of connective tissue that surrounds muscles, providing support and structure. It contains nerve endings that can sense and send pain signals. Muscles and tendons work together to coordinate skeletal movement and provide stabilization at rest and during work, while bones protect the spinal cord and provide greater structural integrity, said Colla. Each piece of the horse’s back anatomy allows him to flex and extend both laterally (side-to-side) and longitudinally (dorsal-to-ventral) during forward and back global body movements—coordinated movements that utilize multiple muscle groups across the entire body to generate significant motion.
Dysfunction in the Equine Back
“Anything that impairs the physiological and biomechanical activities (of the spine) is considered dysfunction,” said Colla. Mechanical dysfunction renders tissues unable to execute their expected function and frequently has high clinical relevance, he added. Dysfunction caused by pain can be acute (conditions that develop suddenly and are often severe but short-lived), subacute (less sudden/severe), or chronic and observed in the horse’s posture, during palpation, and in spinal mobilizations.
“Horses can demonstrate normal, reduced, or increased spinal range of motion during examinations,” said Colla. This might be isolated to one joint or a whole segment due to bony changes, adhesions, abnormal muscle tone, or fascia pain, he added. “The clinical relevance of range of motion changes can vary but is usually associated with other dysfunctions.”
Veterinarians might also observe misalignments in the horse’s spine during examination, which can be isolated or evident throughout an entire segment of the spine. Misalignment can be congenital (present at birth) or acquired (developed after birth due to external factors) and generally has a variable clinical significance, said Colla.
Assessing Equine Back Pain
During a clinical examination, veterinarians should inspect the standing horse’s structure, noting any abnormalities or pathologies (disease or damage) found using palpation or imaging. However, the functional assessment allows practitioners to determine the clinical relevance of these findings and determine whether they affect the horse in his work, said Colla. “The functional assessment should be dynamic and include performance-related work.”
During an assessment Colla said veterinarians should ask clients to describe how long a horse has shown signs of back pain, characteristics of the horse’s pain, previous treatments and their successes, current athletic performance, and intended future use. They should inspect the horse both at rest and in motion and observe muscle development and any asymmetries. Then, using light palpation, they should locate any vertebral misalignment, increased temperature on any part of the back, or abnormal pain sensations.
“Gradually increase force applied to any structures of interest,” said Colla. “Find trigger points and put pressure on exactly that point to observe the horse’s reaction.”
Veterinarians can also observe how the horse moves during spinal mobilization exercises including sternal lifts, lateral bending/rotation, and lumbosacral flexions, said Colla.
Using objective measurement tools can help veterinarians accurately quantify abnormalities in a horse’s back. Colla said he often uses a flexible ruler to draw the contour of a horse’s spine to determine if his posture changes at any point during the rehabilitation, a pressure algometer to quantify pain, and a noncontact infrared thermometer to measure any areas of increased heat. He also takes pictures of the horse to refer to later if needed.
Diagnosing and Treating Equine Back Pain
“For horses with mechanical dysfunction, (veterinarians) can take radiographs, ultrasound, computed tomography, or bone scan (or a combination of several) to help determine the site of dysfunction,” said Colla.
In horses with dysfunction caused by pain, he uses these imaging modalities to locate any pathologies in the back. He also recommends manual therapies, systemic or local medications, acupuncture, extracorporeal shock wave therapy, and therapeutic exercises for rehabilitation.
Colla treats horses with range-of-motion restrictions using therapeutic exercises, manual therapies, and in cases of misalignment, chiropractic adjustment. The only way to treat misalignments is with chiropractic adjustments, he added.
Take-Home Message
Diagnostic technologies and treatments for equine back pain have improved in recent years, but clinical examination and functional assessment are still important for locating clinically relevant pathologies in a horse’s back. Veterinarians should approach each patient as an individual and develop a treatment plan based on the horse’s unique pain and the owner’s plans for the animal.
