Arthritis: The causes of arthritis

By Gil Riley

How to...

19 November 2009 09:42

Far from being a life sentence, with the right approach, it's possible to fight arthritis and give your horse an active, enjoyable life. Vet Gil Riley helps us prepare for battle.

Age

As in people, the older the horse becomes, the more likely he is to develop arthritis. The accumulation of small amounts of damage over a longer period of time eventually leads to the destructive cycle of damage becoming established in a joint. Plus, as a horse ages, the mechanisms that maintain the tissues within the joint become less potent. This leads to a deterioration of the cartilage covering the bone ends, friction developing and, again, the vicious cycle of inflammation.

Workload

Horses most commonly affected by arthritis are those who put their joints through a lot of work over a prolonged period. The joints affected are usually those that are asked to absorb the greatest amount of concussion. For example, show jumpers are prone to arthritis in their forelegs because of the large concussive forces involved on landing. In dressage horses, on the other hand, the hind end bears much of the workload, and so the hindleg joints most often affected are the fetlocks and hocks.

Conformation

Conformation has a large role to play, as it can greatly influence the ability of the horse’s legs to deal with concussion: 

1. If a horse has overly upright forelimbs, he will be more likely to develop osteoarthritis of the fetlock joints.

2. A horse with an overly upright hindleg is more likely to develop arthritis of the hock joints – the same applies to those with sickle hocks.

3. Horses that are back at the knee or have offset (bench) knees are more likely to develop osteoarthritis of the knees.

4. Horses with one front foot more upright (boxy) than the other are more likely to develop arthritis of the coffin and pastern joints.

Work surface

As a general rule, the less forgiving the surface a horse is regularly worked on, the more likely he is to develop osteoarthritis. This is because the harder ground will create much greater concussive forces for the leg joints to absorb.