The animal is thrown by the hobbles upon the side of the leg which is to be operated on.  The cannon of the upper fore-limb is then fixed to the cannon of the upper hind, as described under the section of this chapter devoted to the methods of restraint, and the lower limb freed from the hobbles and drawn forward by an assistant by means of a stout piece of cord round the pastern.

An alternative method of holding the limb is to bind both fore-legs together above the knee by means of the side-line run round a few times in the form of the figure 8, and then fastened off.  As in the former method, the lower foot is then removed from the hobble, and again held forward by an assistant.  By either method the inside of the limb is operated on first.

[Illustration:  FIG. 57.—­THE ESMARCH RUBBER BANDAGE AND TOURNIQUET.]

Although it is not absolutely necessary, it is an advantage, especially to the inexperienced operator, to apply before operating an Esmarch’s bandage and tourniquet (Fig. 57).  This expels the greater part of the blood from the limb, and renders the operation comparatively bloodless.

[Illustration:  FIG. 58.—­RUBBER TOURNIQUET WITH WOODEN BLOCK.]

The Esmarch bandage is composed of solid rubber, and with it the limb is bandaged tightly from below upwards.  On reaching the knee the tourniquet is stretched round the limb, fastened by means of its buckle and strap, and the bandage removed.  Those who feel they can dispense with the bandage use the tourniquet alone.  For this purpose the form depicted in Fig. 58, and the one in general use at the Royal Veterinary College, is more suitable, on account of its wooden block, which may be placed so as to press on the main artery of supply.

[Illustration:  Fig. 59.  NEURECTOMY BISTOURY.]

Instruments Required.—­These should be at hand in an earthenware or enamelled iron tray containing just sufficient of a 5 per cent. solution of carbolic acid to keep them covered.  Those that are necessary will be a sharp scalpel, or, if preferred, one of the many forms of bistoury devised for the purpose (see Fig. 59), a pair of artery forceps, a needle ready threaded with silk or gut, one of the patterns of neurectomy needle (see Fig. 60), and a pair of blunt-pointed scissors curved on the flat.  It is also an advantage, when once the incision through the skin is made, to employ one of the forms of elastic, self-adjusting tenacula (see Fig. 61) for keeping the edges of the wound apart while searching for the nerve.

[Illustration:  FIG. 60.  NEURECTOMY NEEDLE.]

Incision through the Skin.—­We remember that the plantar nerve of the inner side is in close relation with the internal metacarpal artery, and that both, in company with the internal metacarpal vein, run down the limb in close proximity with the inner border of the flexor tendons.  Also, we remember that the external plantar nerve has no attendant artery, although, like its fellow, it is to be found in close touch with the edge of the flexor tendons.