ringbone

A bony growth on the fetlock, pastern, or coffin bone of a horse’s foot, usually causing lameness.

In farriery, a bony callus or exostosis, the result of inflammation, on one or both pastern-bones of a horse, which sometimes extends to the interphalangeal joints and causes immobility and lameness.

The disease or disordered condition in horses which is caused by ring-bone: as, a horse affected by ring-bone and spavin.

A morbid growth or deposit of bony matter between or on the small pastern and the great pastern bones.

osteoarthritis affecting any of several bones of a horse‘s foot