In this case we advise the injection of the original wound, and also such fistulous openings as may have formed, with the 1 in 1,000 sublimate solution.  Also, in order to avoid the sometimes abortive attempts of the antiseptic pad, to maintain a condition of asepsis around the wound, we advise the continual soaking of the whole foot in a cold antiseptic bath.  This may be either carbolic acid 1 in 20, or—­what is less volatile, perhaps more effectual, and certainly more economical—­perchloride of mercury 1 in 1,000.

It has been our good fortune, even when we have seen the foot almost detached from the limb by the devastating inroads of the pus, to see the suppurative process by this means gradually overcome, a reparative anchylosis set in, and the animal restored to good health and usefulness, if not to soundness.

Once the suppurative process is checked and anchylosis commences, it is good treatment to smartly blister the whole of the region of the coronet, the pastern, and the wound itself with a mixed blister of cantharides and biniodide of mercury, repeated at intervals of a fortnight.  This prevents to some extent further infection of the wound, and assists also in promoting the changes that tend to anchylosis.

(d) ANCHYLOSIS.

The word anchylosis signifies the stiffening of a joint.  When one has read the serious changes occurring within the joint in the more serious forms of arthritis, it is easy to understand how it comes about.  In suppurative arthritis, for instance, we have the synovial membrane destroyed, the articular cartilages partly or wholly obliterated, and the former boundaries of the joint entirely lost.  If the animal lives, nature is bound to make repair of a sort.  The synovial membrane and the articular cartilages utterly destroyed, as we have described, cannot again be replaced.  Nature can only build again from such materials as are left to her.  In this case the material is bone.

It must be remembered, however, that often the bone has been so diseased that spots of necrosis or caries within it are bound to remain unless moved by operative interference.  Such diseased portions, when dealing with the foot, are beyond reach of the surgeon’s knife, and we have no alternative but to allow them to remain.  We get, therefore, in many cases, a condition of rarefactive ostitis occurring side by side with a slowly progressive caries within the bone, while outside is occurring an osteoplastic periostitis.  The concurrence of these conditions leads in time to great increase in size of the parts, together with increasing anchylosis and deformity.

C. NAVICULAR DISEASE.

Definition.—­Chronic inflammatory changes occurring in connection with the navicular bursa, affecting variously the bursa itself, the perforans tendon, or the navicular bone, and characterized by changes in the form of the hoof and persisting lameness.  The disease is commonly noticed in thoroughbreds or in horses of the lighter breeds, and is but seldom observed in heavy cart animals.  Usually it is met with in one or both fore-feet.  Although of extremely rare occurrence, it has been noticed in the hind.