Down to the bone

You may have heard the terms ringbone and sidebone, and while they may sound similar, they are, in fact, quite different conditions, each with its own specific, long-term prognosis. So what are they and what does a diagnosis mean for your horse?

Ringbone

The condition known as ringbone refers to osteoarthritis (OA) of the coffin or pastern joints. Low ringbone is OA in the coffin joint and it affects all types of horses. It’s quite common and usually seen in the front feet. Similarly, high ringbone is OA in the pastern joint (right). It’s more common in heavier breeds such as cobs and draughts and is often seen in the hindlegs. The name ringbone comes from the firm swelling that can develop around the front of the pastern.

Cause and effect

Ringbone is an acquired condition that develops as a result of wear and tear on the joints and, therefore, it tends to be seen in middle-aged and older horses. Many things can contribute to the development of the problem, including genetic predisposition, conformation, nutrition in early life, workload, lifestyle and any previous injury, such as dislocation or fracture.

Horses who work hard on firm ground and those who jump place increased stress on their joints, predisposing to microinjury and subsequent development of OA. However, the problem is also sometimes seen in younger horses and those who have had a seemingly easy life.

Many horses will remain sound during the initial development of ringbone until a threshold of damage is reached, at which point problems are detected. Most commonly lameness is the first abnormality noticed, usually being more obvious on hard ground and on circles, but sometimes swelling across the front of the pastern or a drop in ridden performance – such as refusing jumps – may occur first. Veterinary advice should be sought at this stage.

Top tip

Monitoring your horse’s weight is an important preventative measure for a wide variety of conditions, including OA in its different forms.

Diagnostic methods

Diagnosis is made using a combination of limb palpation and lameness examination that includes nerve or joint blocks and radiography (X-rays). During the early stages, when damage within the joints is limited to the cartilage alone, radiographic abnormalities may be subtle. Sometimes, therefore, advanced imaging modalities such as MRI, CT or bone scanning will be required.

Find out more about ringbone and sidebone in November Horse&Rider – get your copy today!