Hindlimb Proximal Suspensory Desmitis
I recently saw a 12 year old Warmblood gelding with the following history:
Highly accomplished fourth level dressage horse in consistent work and training with 4-6 month history of subtle “poor performance.” Owner has horse on intramuscular Adequan, intravenous Legend, and an oral glucosamine/chondroitin and MSM supplement. Horse receives fairly regular massage therapy and chiropractic care. Owner reports horse has had consistent “hock injections” as “maintenance.” Results of intra articular (joint) injections are varied; owner reports that the injections are becoming more frequent (less time between injections).
This history is not uncommon in English and Western sport horses. Mild to moderate hindlimb lameness is commonly blamed on arthritis in the hock or stifle joints or on sore muscles. And indeed hindlimb lameness is often the result of these conditions. However another possibility should not be overlooked: hindlimb proximal suspensory desmitis (inflammation of the upper suspensory ligament).
Hindlimb proximal suspensory desmitis can be easily missed, as the horse continues to compete for weeks, months or even years, and as performance suffers. Many horse owners assume that ligament problems are evidenced by suddenly hot and swollen limbs. Such a presentation does occur, but more commonly the presentation is subtle (especially in the hindlimbs).
Care must be taken in sport horses–especially those in dressage, barrel racing, cutting & reining, and jumping–when presented with a history similar to the above. A thorough assessment of the sport horse will include consideration of possible upper suspensory ligament damage or inflammation. Of course, clinical history, lameness examination with nerve and/or joint blocks, digital radiography and ultrasound are also essential. The assumption that the horse just needs his “hocks done” or “stifles blistered” can lead to costly and ineffective treatment. Worse, a horse’s competitive career can be shortened or ended in the event of a compromised and untreated upper suspensory ligament.