Description

Sidebone is a condition in which cartilage tissue in the foot ossifies and bony protrusions develop. It is caused by lack of movement within the foot due to improper shoeing and/or trimming or by trauma to the foot.

Since cartilage does not have blood vessels that supply nutrients, the cells are normally nourished by "diffusion" through physical vibration and movement as they interact with surrounding tissues.

Without this movement, cartilage tissue becomes damaged. For the most part, sidebone has been largely ignored by veterinarians and horse handlers who do not see it as a problem, partly because it doesn't lead to lameness in most cases.

Symptoms

• Small areas of calcification felt when palpated
• Ossification of cartilage usually found when X-rayed

Causes

The main causes of sidebone are hoof concussion, repetitive motion injury, imbalances caused by conformation faults, and improper trimming and shoeing. Improper trimming and shoeing may be factors in hoof concussion and repetitive motion injury since they lead to faulty movement of the cartilage and bones within the foot.

Heavy horses working on hard surfaces are most prone to sidebone, and it is often seen in hunters and jumpers. The development of sidebone often indicates that other changes to a horse's feet may be occurring, such as navicular disease or ringbone, as a result of the decrease in the natural shock absorption capacity of the horse's hoof.

Some horses appear to have a hereditary predisposition to sidebone because of conformation. Horses with narrow, upright feet or unbalanced feet, especially those that toe in or toe out, seem prone to the condition. Also, draft horses or horses with heavier builds are more likely to develop sidebone than lighter weight horses.

Prevention

Keeping the horse's hoofs properly trimmed and shod is the best prevention. The farrier should use trimming and shoeing techniques that maximize movement and circulation in the foot, leading to good cartilage health. Barefoot horses that have properly shaped feet and are allowed freedom of movement seldom get sidebone. Extra sole, wall, and bar material, and steel shoes should be avoided whenever possible.

Treatment

Stall rest and non-steroidal anti-inflammatory drugs are helpful in the treatment of sidebone. If proper shoeing and trimming, rest, and anti-inflammatory drug treatment don't work, neurectomy of the palmar digital nerves by a veterinarian may be necessary. In this case, care must be taken that the horse does not suffer further injury because of the lack of pain created by severing the digital nerves in the foot .