Suspensory apparatus breakdown
Suspensory apparatus breakdown is caused caused by excessive forces being applied due to overextension of the fetlock and most commonly occur in racehorses exercising at high speeds. The animal will show a sudden lameness and will walked with a ‘dropped’ fetlock, i.e. fetlock joint drops to the ground and the pastern is nearly horizontal.
Diagnosis
The characteristic gait is usually enough for an initial diagnosis to be made, however, X-rays and ultrasound scanning are required to assess the damage, i.e. the presence of any boney damage.
Treatment
The limb can be immobilized with the fetlock flexed for a prolonged period. This treatment will not usually provide a pain-free limb and euthanasia is often indicated. Arthrodesis (fusion) of the joint can be performed as a salvage procedure for pasture soundness.