iest means of removing the surface dirt. Afterwards the foot
should be soaked for some time in a reliable antiseptic solution, a 1 in
1,000 solution of perchloride of mercury being the most suitable. When
removed from the solution the foot must be packed round with wool or
tow impregnated with corrosive sublimate, and then bandaged, the whole
afterwards wrapped in a thick cloth, or protected with a boot.

On the following day the animal is brought out and cast, and the foot
desired to be operated on firmly secured, after the manner described on p.
81. The bandages and sublimate pads are then removed, and the skin of
the coronet over the seat of operation shaved of hair. An Esmarch rubber
bandage is next run up the limb, and the tourniquet applied, thus rendering
the operation a nearly bloodless one.

This done, the animal is chloroformed, and an antiseptic douche played over
the foot.

So far, the steps in the operation are common to all methods. There are
now, however, three slightly differing modes of extirpating the cartilage,
which modes vary simply according to the structures severed by the knife.

_First Method_.--This is the oldest method of the three, and consists in
making (1) a horizontal incision through the sensitive laminae along the
lower border of the cartilage, and (2) a vertical incision through the skin
of the coronet, the coronary cushion, and a portion of the sensitive laminae
(see Fig. 139).

The flaps (Fig. 139, _a, a_) are now held back by tenaculae, and the whole
of the cartilage, or only the necrosed portion, carefully excised by means
of right- and left-handed sage-knives. Fistulous openings in either of the
flaps _a, a_ must now be carefully curetted and dressed, and the flaps
allowed to fall into position. They are then sutured with carbolized gut,
and the wound finally dressed as to be described later (p. 357).

[Illustration: FIG. 139.--EXCISION OF THE LATERAL CARTILAGE (OLD METHOD).
The wall covering the lateral cartilage first thinned and stripped off; the
two flaps (_a, a_) of skin and the coronary cushion made by the vertical
incision turned back. _a_, The operation flaps; _b_, the exposed cartilage;
_c_, the sensitive laminae; _d_, the coronary cushion.]

_Second Method (after Holler and Frick_[A]).--These operators deem it wise
to leave untouched the skin of the coronet and the coronary cushion. They
therefore make their first incision along the lower border of the coronary
cush