Osteochondrosis
The simplest definition or osteochondrosis or 'OCD' is failure of endochondral ossification. What this means is that the bone beneath the cartilage at the ends of the bone has not developed correctly, and a cartilage plug has remained in situ that may become loose (a joint mouse) in time. As young horses develop the OC lesion may cause the joint to become very effusive; the inflammation being caused by the improperly formed bone may damage the remainder of the joint, and thus your veterinarian may advise you to remove it. The cause of osteochondrosis is unknown but several theories remain including nutritional and mineral imbalances, trauma and hereditary factors. Glucosamine is often indicated in the healing of OCD lesion especially for the first few months after surgical debridement of such a lesion to help the cartilage repair.