High Ringbone & Low Ringbone

Ringbone is a lay term used to describe an osteoarthritis that affects the pastern joints in both the front and hind limbs of horses.  Long term concussion, hard work, nutritional imbalances, and inherited poor conformation (upright pasterns or weak collateral ligaments of the pastern joints), encourage the development of ringbone in older horses.
It is a progressive, degenerative, performance limiting condition. It is however one of many possible causes of lameness that occurs in the lower limb of the horse. Many of these conditions also produce very similar initial signs. For this reason it is important to have your horse evaluated by your vet in order to accurately diagnose and treat the condition.

Ringbone is divided into categories based on location -that is, high or low ringbone, and type - articular or non-articular. These categories are important as they often determine the horse's long-term prognosis. The prognosis for low ringbone being poor.

Articular ringbone is due to osteoarthritis of the pastern or coffin joint and generally occurs in horses used for performance (other than racing) that involves quick stops, twists and turns, such as western performance or polo. Horses with poor conformation, especially base narrow or wide, toed in or out and upright in the pasterns are also predisposed to articular ringbone.

Non-articular ringbone may result from inflammation of the bone covering (perisotitis) and trauma.

Articular ringbone is a fairly serious type of arthritis that may affect either of the two joints. High ringbone occurs at the joint of the long and short pastern articulation. Low ringbone occurs at the short pastern - coffin bone articulation.

Non-articular ringbone refers to new bone growth on any of the three bones. This type of ringbone is also divided into high (upper pastern) and low (short pastern and coffin bone).

Ringbone more commonly occurs on the front legs, and owners may initially observe a moderate-to-severe lameness with a firm swelling in the pastern area. Heat and pain on deep pressure may also be evident. As the disease progresses, a bony deformation in the pastern or coffin joint region may develop. As the lameness becomes more progressive, a firm, cool swelling will be evident over the pastern region.