OCD is a degenerative joint disease ( a type of developmental orthopaedic disease or DOD) usually found in young, rapidly growing horses who will eventually mature to over 15 hands. As may be expected, Friesians can be prone to the disease, simply due to their size. OCD occurs when cartilage at the end of growing bones, instead of hardening into bone, begins to break down. As a result of this break-down, small bits of cartilage may break completely or partially off and harden into bone cysts, which irritate the area of the joint, causing a build up of fluid (swelling), and pain (lameness).

OCD can be identified by lameness or swelling commonly in the hocks, stifles and fetlocks of young horses, especially those who have recently entered training or become more active, putting more stress on their growing joints. OCD can also cause locking stifles. Although OCD is commonly identified by a lameness, in some cases there may be no obvious symptoms, in which case the problem will likely clear up on it’s own. The cause of OCD has been linked to nutrition, particularly mineral imbalances, as well as trauma from excessive physical exercise. The disease is also thought to be at least somewhat genetically inheritable.

OCD can be officially diagnosed by x-rays and other veterinary procedures. Once determined that a lameness is in fact caused by OCD, traditional treatment options include joint injections, stall rest and a change in diet, or surgery to remove the floating bone fragments from the joint. Left untreated, OCD can cause significant, long-term joint damage, and the fullness of recovery after treatment varies depending upon the individual.

Suggested Reading:

[Liphook Equine Hospital: Osteochondritis Dissecans (OCD)] – An informative article on OCD, it’s causes, treatment and prevention.