ringbone, bony outgrowth on the front and sides of the pastern bones of a horse's foot, resulting from inflammation or faulty conformation of the bones. The outgrowths increase with sprains and other injuries. Ringbone often produces lameness and is difficult to remedy. It may be controlled by keeping the feet of young animals in proper balance by correct trimming. In cases where swelling above the top edge of the hoof wall has developed and lameness is marked, the sensory nerves may have to be cut.