Degenerative joint disease (DJD) is another name for osteoarthritis, which is the most common type of arthritis in horses. It is a chronic, (i.e. long-standing) disease in which the cartilage on the ends of bones wears down, resulting in loss of joint mobility, swelling, heat and pain.
It is a common cause of lameness, reduced performance or stiffness, especially among older horses, that often improves with gentle exercise. It can affect a single joint or several joints simultaneously. It was the second highest source of insurance claims during 2018 according to Petplan Equine¹. In more severe cases it is a common cause for retirement of an older horse.
Bone spavin (arthritis of the lower hock joints) and ringbone (arthritis of the pastern or coffin joints) are two of the best-known examples, but any joints are at risk.
The causes of DJD are not clear and currently the condition cannot be prevented. Once established, it can only be managed, not cured. Management must aim to reduce pain and minimise progression of the condition by stimulating the cartilage and inhibiting further degradation.
Another serious type of arthritis found in horses is septic arthritis. This is an acute form of DJD caused by a bacterial infection inside a joint. It is typically seen in foals that have compromised immune systems or systemic disease, as well as in horses of any age that have suffered a traumatic injury near a joint. In all such cases, infection enters the joint cavity, which can be difficult to treat. Unless a septic joint is treated rapidly and aggressively, usually by flushing out the contamination, it can be career-ending.