What is ringbone?

• A. Inflammation of the fetlock
• B. Fracture of the cannon bone
• C. Bony growth on the pastern and coffin joint, exostosis
• D. Degenerative joint disease of the coffin joint

Answer: (C)

Ringbone is a bony growth around the joints of the horse’s pastern and coffin region, an exostosis. This extra bone forms as the joint responds to chronic stress, concussion, or arthritis, and it can show up as a hard ring or spur along the pastern area. It’s not inflammation of the fetlock (which is a different joint up higher) and not a fracture of the cannon bone. While degenerative changes can affect the coffin joint, ringbone specifically describes the bone proliferation around those joints, and it can occur in the high (pastern joint) or low (coffin joint) locations.