This section is from the book "The Farmers Ready Reference Or Hand Book Of Diseases Of Horses And Cattle", by S. C. Orr. . Also available from Amazon: The Farmer's Ready Reference;.
These are enlargements just above the top of the hoof near the back part of the quarter. They are the ossification, or changing into bone, of the lateral cartilages that surround and extend back from the wings of the coffin bone. There may be one on each side of the foot or it may be only on one side. They may also be on one or both feet. There will be lameness, but it is not so serious as ringbone.
Treatment. - The shoe must be removed and the hoof cut away underneath the enlargement; if the frog strikes the ground all the better. If there is much inflammation reduce it with cold water, and it would be well to stand the feet in cold water for several hours each day for several days until the unnatural heat is all gone. Then apply the Biniodide of Mercury Blister and repeat in three weeks. Give the horse complete rest.