Long known as a problem condition in older, working horses, ringbone continues to be a concern for horse owners around the world. Ringbone is a condition that includes swelling and changes to the bones and joints of the pastern in either the front or back legs. Ringbone is basically a new bony growth that occurs on any one of the bones in the pastern, it can occur in the pastern joint itself (high ringbone) or can occur lower in the foot in the coffin joint (low ringbone).
Ringbone is a form of osteoarthritis and may be a result of several factors. The more factors that are present or have occurred in the horse's life the more severe and problematic the ringbone is likely to be. The major cause of ringbone is repetitive trauma to the pastern through sudden stops, turns and changes of direction. Many western stock horses, cutting horses and polo ponies develop ringbone as they are constantly and suddenly changing directions at high speeds and with great frequency.
Conformation problems that result in the pastern being too straight up and down add more jarring and concussion to the joint with each step. If the horse gains weight or is used for intense exercise the damage will be more severe and pronounced. Horses that have pin-toes or toe-out or splay their legs often have more problems with ringbone as they mature due to uneven wear on the sides of the joint.
Any kind of injury or infection to the foot or pastern area can result in ringbone. Punctures, injuries from getting the foot caught in wire or even fractures and strains that may occur in normal riding or exercise conditions can contribute to the problem. OCD lesions have been found in some horses with ringbone so there may be developmental issues with bone development at early stages that may also contribute to the likelihood of the horse developing ringbone.
Typical signs will include swelling or lumps on the pastern either on one side or both, and the area will feel hot to the touch. The horse will be sensitive to pressure or weight on the limb and will often limp and have very short strides when moving on the affected foot. As the bony growth continues it is more likely that the range of motion of the pastern will be restricted and the horse will adjust to the shorter strides, however it will progressively become worse.
If conformation problems are causing the ringbone corrective shoeing is required at the earliest possible time to prevent further degeneration of the joint. Management including non-steroid anti-inflammatories and ice packs on the pastern can help reduce the swelling. Pain reduction therapies will also play an important role in the initial treatment. Low dosage corticosteriods injected directly into the joint can also help minimize damage.
Horses with ringbone can often continue to be used as pleasure horses provided they are warmed up, routinely checked for correct balance and soundness, and provided with corrective shoes. For more severe conditions however fusion of the joint and cutting the nerve to the pastern is required to manage the pain of the condition.