In such cases we have derived excellent results with the actual cautery.  The animal is cast, the foot firmly secured by fastening it upon the cannon of another limb, and the animal chloroformed.  A practical point to be remembered in this connection is that all necessary fixing of the limb is easier performed if the chloroform is administered first.  With the patient thus secured we first of all ascertain by means of the probe whether or no the non-healing of the wound is due to the presence of a fistula.  Decided in the negative, we take an ordinary flat firing-iron, and with it cut away a portion of the skin immediately around the still open wound, carrying our incisions deep enough to ‘scoop’ out a large portion of the new inflammatory tissue beneath.  With the loss of pressure from beneath, occasioned by the removal of so much of the cicatricial tissue, the epidermis the more readily closes over the wound.  To a large extent also this new growth of epidermis is helped by the renewal of the inflammatory phenomena brought into being with the cauterization.

2.  SUB-HORNY QUITTOR.

Definition.—­A fistulous wound of the foot in which the lower and blind end of the fistula is situated below the level of the coronary margin of the wall.

Causes.—­These, again, will be practically the same as those mentioned in the cause of cutaneous quittor—­namely, bruises, punctures, wounds—­in fact, any injury upon the coronet severe enough to cause death of tissue and a suppurating wound.  We may thus expect sub-horny quittor to follow upon treads, overreach, accidental injuries with the stable-fork, and kicks from other animals.

Sub-horny quittor may also arise without original injury at all to the coronet.  Either from a violent blow upon the hoof, or from the animal himself kicking violently against a wall, death of a portion of the sensitive structures takes place within the hoof, suppuration ensues, and the formation of quittor commences.  With the escape of the pus at the coronet the quittor is fully formed.

Any other diseased condition of the foot in which suppuration is present may in like manner terminate in quittor.  In complicated sand-crack, suppurating corn, or in ordinary pricked foot quittor may be a sequel.  In these conditions the pus formation either goes unnoticed or is neglected, and after seriously invading the sensitive structures within the hoof, breaks out at the coronet.  Again, too, as with the simpler form of quittor, and as with coronitis, we may always regard as a predisposing cause the action of excessive cold in promoting septic infection of the wound when occurring at the coronet.

Symptoms and Diagnosis.—­Where the fistulous wound has had its starting-point in an injury to the coronet diagnosis is, of course, easy.  The history of the case explains it.  Nothing in this instance remains but to probe the opening, and ascertain its direction, depth, and extent.