Degenerative joint disease, or arthritis as it is more commonly known, affects the cartilage on the ends of the bones, resulting in changes to the underlying bones themselves.
It is a common cause of lameness, reduced performance or stiffness, especially among older horses, that often improve with gentle exercise. Itcan affect a single joint or several joints simultaneously.
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 lower limb joints are at risk.
Managing the condition
The causes of arthritis are not clear and currently cannot be prevented. Once arthritis is 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.
Anything that aids joint function may result in reduced pain and therefore reduce lameness and enhance performance. Equally, a reduction in workload can alleviate the signs.
Scientific studies have shown that Glycosaminoglycan polysulphate (Adequan) and various sodium hyaluronan (formerly called hyaluronate) products, such as Hylartil and Hyonate, can have significant positive effects on arthritic joints in the horse.
These drugs help halt degenerative changes as well as indirectly reducing pain and lameness. It also seems that small quantities of the drugs can have a significant effect.
However, experience shows that these drugs have little benefit when treated advanced degenerative changes, – their real value is treating the early stages of arthritis. Bute and other similar drugs have a role, too.
A plethora of nutritional supplements claiming to promote cartilage repair and protect against further damage are now available.
They vary in their constituents, many containing chondroitin sulphate and glucosamine, others glucosamine alone, or a mixture of plants and herbs including meadowsweet, nettle and yucca, with devil’s claw.