A ring-bone is an enlargement extending over the front, and sometimes also over the back, of the pastern. It consists of a diffused bony excrescence growing out of or upon the large or small pastern bone, or both. When affecting the former it is described as high ring-bone (fig. 314), when the latter, as low ring-bone (fig. 313). It is common to all classes of horses, but more especially prevalent in cart-horses and thoroughbreds.
Fig. 314. -"High "Ring-Bone.
Horses with upright pasterns, and animals with pasterns of undue length, are specially predisposed to it. The exciting causes are chiefly blows, concussion, and sprains to the joints. Fracture of the pastern is invariably followed by ring-bone in the form of a reparative callus. It is also induced by the too early and severe work imposed on young, undeveloped animals, and especially when attended with bad shoeing, as where the heels are thrown up too high and an upright position given to the limb.
A hard, unyielding enlargement, more or less prominent and extensive, is the characteristic indication of the disease. It passes across the front of one or the other of the pastern bones, and sometimes encroaches on the posterior surface. The degree and character of the lameness will vary with the position of the growth. When situated on the small pastern, within the hoof, the lameness is very considerable, and the foot is brought to the ground with the bearing full on the heel. If it be situated behind, the fetlock joint is partially flexed and the weight is thrown on the toe. In other situations the action is not so conspicuously altered, but in all there is more or less severe lameness, with swelling, heat, and tenderness of the part.
To subdue existing inflammation should be our first aim. In this connection a dose of physic, with perfect rest, and the application of hot fomentations and bandaging, must be resorted to; after which a repetition of blisters, or the application of the actual cautery to the pastern, will be required to check further growth of the excrescence and to effect its reduction. A long rest is often needed before pain and lameness are removed, and in many instances this desired result is never attained.