Osteochondritis Dissecans: A Common but Complex Disease

“Osteochondrosis is a disease in which the cartilage at the end of long bones, such as bones in the leg, fails to develop normally,” says Annette McCoy, DVM, PhD, Dipl. ACVS, an equine surgeon at the University of Illinois Veterinary Teaching Hospital in Urbana. “Sometimes this disease results in a fragment of bone or cartilage breaking off on the surface of the joint, and that problem is known as osteochondritis dissecans.”

Up to 80% of young horses in some breeds develop osteochondritis dissecans, McCoy says. Although any breed of horse can be affected, Standardbreds and Warmbloods are considered to be predisposed to osteochondritis dissecans.

Any joint can be affected. The joints most commonly affected in horses are the fetlock, hock, and stifle. It is not uncommon to have