Bearing these landmarks in mind, we feel for the nerve in the hollow just above the fetlock-joint by noting the pulsations of the artery, and determining the edge of the flexor tendons.  This done, a clean incision is made with the bistoury or the scalpel in the direction of the vessels.  The incision should be made firmly and decisively, so that the skin may be cleanly penetrated with one clear cut.  If judiciously made, little else in the shape of dissection will be needed.

[Illustration:  FIG. 61.—­DOUBLE TENACULUM.]

It is now that the double tenaculum (Fig. 61) is applied.  One clip is fixed to the anterior edge of the wound, and the other carried beneath the limb and made to grasp the posterior edge.  If found desirable to keep the edges of the wound apart, and no tenaculum to hand, the same end may be accomplished by means of a needle and silk.  In like manner as is the tenaculum, the silk is attached to one edge of the wound, carried under the limb, and firmly secured to the other.

Having made the incision, the wound should be wiped free from blood by means of a pledget of cotton-wool previously soaked in a carbolic acid solution and squeezed dry.  At the bottom of the wound will now be seen the glistening white sheath, containing the vein, artery, and nerve.  This should be picked up with the forceps, and a further incision made with the bistoury.  Care should be exercised in making this second incision, or the artery may accidentally be opened.  If an ordinary scalpel is used, the lower end of the sheath should be picked up and the point of the scalpel inserted through it.  With the cutting edge of the scalpel turned towards the opening of the wound, the sheath is then slit from below upwards.  The second incision satisfactorily made, the wound is again wiped dry, and the nerve seen as a piece of white, curled string in the posterior portion of the wound.

At this stage it is advisable to accurately ascertain whether what we have taken to be the nerve actually is it.  This is done by taking it up with the forceps and giving it a sharp tweeze.  A sudden struggle on the part of the patient will then leave no doubt in the operator’s mind that it is the nerve he has interfered with.

Section of the Nerve.—­The neurectomy needle (Fig. 60) is now taken, and, excluding the other structures, passed under the nerve.  A piece of stout silk or ordinary string is then threaded through the eye of the needle, the needle withdrawn, and the silk left in position under the nerve.  The silk is now tied in a loop, and the nerve by this means gently lifted from its bed.  With the curved scissors or the scalpel it is severed as high up as is possible.  The lower end of the severed nerve is then grasped firmly with the forceps, pulled downwards as far as possible, and then cut off.  At least an inch of the nerve should be excised.

The animal is then turned over, and the opposite side of the limb operated on in the same manner.