Equine Health

Case Report: Sport Horse Medicine

Damaged Ligament

Patient: 10 yr old TB x Warmblood Mare

Intended Use: Dressage

History: This mare was in her third day of competition in a dressage show at Prix St. George level when a judge noticed the mare was short in the right hind leg during her test. The judge felt that the mare was getting progressively worse and brought this to the rider’s attention. The rider noticed swelling in the right hind leg after dismounting and promptly stalled the horse and applied ice while awaiting veterinary attention.

Physical Examination: On physical examination the mare was 4/5 lame (severe) on the right hind at a walk and exhibited a toe stabbing gait. Heat, swelling, and pain was present just below the hock. Flexion of the leg was very painful and was resisted by the horse.

Diagnostic thermographic imaging of the leg revealed an area of heat on the distal back aspect of the hock that coincided with the area of pain and swelling. This thermal pattern was consistent with proximal suspensory desmitis.

Ultrasonic imaging of the proximal suspensory ligament showed a 30% increase in size of the right proximal suspensory ligament as compared to the left hind (the right suspensory is marked by a white “x”). The ultrasound also showed a disruption in the fiber pattern of the ligament and a “core lesion," or a centralized area of tearing within the ligament.

Diagnosis: Proximal Suspensory Desmitis of the right hind leg.

Treatment: Treatment was initiated immediately after the diagnosis was made. In ligament injury it is extremely beneficial to have an accurate diagnosis and to implement treatment before further damage can be done to the leg. Initially the horse was put on stall rest, heat and cold therapy was begun and phenylbutazone was given orally. A week after the injury the ligament and surrounding tissue was injected with hyaluronic acid (Legend) corticosteroids.

Discussion: Early diagnosis and prompt therapy is the key to a better prognosis in these injuries. Often horses will appear sound a few days after the initial injury, but in reality the ligament is severely damaged and will only truly start to heal with medical intervention and an extended rest and rehabilitation period. It is also important that the ligament is examined with imaging to assess when and if the horse can go back into training.