When the suppuration has under-run the horny frog there should be no hesitation in at once removing all the horn that is visibly separated from the sensitive structures beneath.

When the os pedis is splintered and carious, a portion of the sole round the wound is removed, and the bone exposed.  The diseased portion is scraped away either with a curette or with the point of the drawing-knife.  In this case the only after-treatment called for is the application of suitable antiseptic dressings.

When necrosis of the plantar aponeurosis has occurred.  We have already pointed out the tendency there is in this case for the wound to maintain a fistulous character, and lead to the formation of abscesses in the hollow of the heel.  With a wound in this position, as with a wound in any other, the only method of avoiding this termination consists in removing all that is visibly diseased, whether it be soft structures, bone, ligament, or tendon, and giving the wound free drainage.

This can only be done by removing the horny sole and frog, and cutting boldly down upon the structures beneath.  The operation is known as resection of the plantar aponeurosis, or the complete operation for gathered nail.

Practised for some years on the Continent, this operation, on account of its gravity, has been avoided by English veterinarians.  From reported cases, however, it appears often to be followed by success.

That there is a large element of risk in the operation is quite evident, if only from the two facts mentioned beneath: 

1.  That the close attachment of the plantar aponeurosis to the navicular bursa, and the nearness of both to the pedal articulation, render penetration of a synovial sac or a joint cavity extremely likely.

2.  That there is always great difficulty in maintaining strict asepsis of the foot, more especially if it is a hind one.

On the other hand, it may be argued that equal risk to the patient is run in allowing him to remain with a disease (and that disease a progressive one) of the structures so closely antiguous to the navicular bursa and the pedal articulation.

If only for that reason we give the operation brief mention here.

The animal is prepared in the usual way for the operating bed; the foot soaked for a day or two previously in a strong antiseptic solution, the patient cast and chloroformed, and the operation proceeded with.

[Illustration:  FIG. 106.—­’CURETTE,’ OR VOLKMANN’S SPOON.]

An Esmarch’s bandage should be first applied, and a tourniquet afterwards placed higher up on the limb.  The foot is then secured as described in an earlier chapter, and the whole of the horny structures of the lower surface of the foot (the sole, the frog, and the bars) pared until quite near the sensitive structures, or, if under-run with pus, stripped off entirely.  An incision is then made in each lateral