Sorting out Spavins

by Christine Barakat

A bump on your horse's hock can be a big deal...or absolutely nothing at all. In common parlance, hock lumps are identified as spavins, but among the three spavin types, the worry quotient varies greatly. The hock lump's location and consistency say a lot about prognosis.

A hard lump on the hock's inside lower aspect toward the front of the joint is most likely a bone spavin, ossification associated with degenerative arthritis. This most common cause of chronic hind-limb lameness in horses produces a gradual disability that tends to worsen with work. A horse in undemanding activities may continue to perform comfortably with a bone spavin. Some horses with bone spavin become sound in one or two years. Treatment options range from specialized shoeing to surgery, depending on the severity of the condition.

A soft swelling on the inside upper aspect of the hock is a bog spavin caused by stretching of the joint capsule there. The stretched capsule then bulges beyond its normal limits. If you press on the bulge, it may appear on the outside back portion of the hock as the capsule bulges in the opposite direction, and it dissipates slowly. Unless they are recent or the result of serious trauma that otherwise damaged the joint, bog spavins typically cause no lameness or, at most, mild unevenness of the gait.

A soft, squishy swelling running up the front and toward the inside of the hock that disappears immediately with pressure, only to reappear instantly, is probably a blood spavin. The palpable lump is a displaced vein that ordinarily would be far around to the inside of the joint. Blood spavins cause no lameness or other troubles.