Practical points to be remembered in fitting plates of this description to the feet are:  The plate must never quite reach the shoe, or it will participate in the concussion of progression, and so loosen the screws that hold it in place.  For the same reason, that portion of the sole adjoining the piece of horn removed must have its bearing on the shoe relieved.  The screws holding the plate should be oiled to prevent rusting, and should take an oblique direction in order to obtain as great a hold as possible on the wall.

When excision is deemed unwise or unnecessary, treatment should be directed towards maintaining the cavity in a state of asepsis.  To this end it should be thoroughly cleaned of its contents, and afterwards dressed with medicated tow.  The ordinary tar and grease stopping is as suitable as any.  This, together with the tow, is tightly plugged into the opening and kept in position by a wide-webbed shoe.  Instead of the tar stopping and the tow, there may be used with advantage the artificial hoof-horn of Defay (see p. 152).  Before using this the cavity should again be thoroughly cleaned out, and should in addition be mopped out with ether.  The latter injunction is important, as unless the grease is thus first removed, the composition will fail to adhere to the horn.  With the cavity thus cleaned and prepared, the artificial horn, melted ready to hand, is poured into it and allowed to set.

In every case, no matter what else the treatment, the bearing of the horn adjacent to the lesion should be removed from the shoe.

Whether practising the method of plugging the cavity or that of excision of the wall external to it, attempts to quickly obtain a new growth of horn from the coronet should be made.  To further that, frequent stimulant applications should be used.  Ointment of Biniodide of Mercury 1 in 8, of Cantharides 1 in 8, or the ordinary Oil of Cantharides, either will serve.

3.  KERAPHYLLOCELE.

Definition.—­By this term is indicated an enlargement forming on the inner surface of the wall.  In shape and extent these enlargements vary.  Usually they are rounded and extend from the coronary cushion to the sole, sometimes only as thick as an ordinary goose-quill, at other times reaching the size of one’s finger.  Often they are irregular in formation and flattened from side to side.

[Illustration:  FIG. 132.—­A PORTION OF THE HORN OF THE WALL AT THE TOE REMOVED IN ORDER TO SHOW A KERAPHYLLOCELE ON ITS INNER SURFACE.]

Causes.—­Keraphyllocele is very often a sequel to the changes occurring at the toe in laminitis.  Probably, however, the most common cause is an injury upon, or a crack through, the wall.  It may thus occur from excessive hammering of the foot, from violent kicking against a wall or the stable fittings, and from the injury to the coronet known as ‘tread.’  It may also occur as a sequel to complicated sand-crack, and to chronic corn.