he pea-green colour of the affected parts, they
must be _carefully_ excised. Care should be taken in so doing to carry the
line of excision some little distance around the visibly affected parts.
This is done that we may be quite certain nothing at all remains calculated
to give rise to further trouble.

It goes without saying that, in addition to the necrosed cartilage, all
other diseased and necrotic tissues should also be removed. The os pedis is
occasionally found necrotic just where the cartilage joins it, or it may be
that a small portion of the sensitive laminae, by reason of its _liver-red_
or even gray coloration, gives evidence of death of the part.

The former must be well curetted, and the latter cleaned carefully with a
scalpel and forceps.

[Illustration: FIG. 142.--PARTIAL EXCISION OF THE LATERAL CARTILAGE BY
REMOVING A PORTION OF THE CORONARY CUSHION. The dotted lines show the
outline of the wedge-shaped portion of structures to be removed, including
skin, coronary cushion, horn, and sensitive laminae. _a_, The opening of the
fistula.]

The operation finished, the foot is again douched in an antiseptic
solution, the wound mopped dry with carbolized tow, dressed with either of
the dressings described on page 358, and finally bandaged. The dressing
should be changed every three days only, unless in the meanwhile pawing
movements and other symptoms of distress indicate their removal.

The length of coronary cushion removed in this operation is from 1/4 to 1/2
inch (we ourselves, however, have seen it more), and yet its loss seems to
occasion no serious after-trouble beyond a slight deformity of the parts
beneath. The sensitive structures become sufficiently covered with horn,
and the animal in nearly every case is returned to work, while in a great
many instances he may also trot perfectly sound.

Simple though the operation may appear, and apparently rough in its method,
it is nevertheless successful in effecting a cure in cases where blisters,
plugging, injections, and other means have failed.

Mr. W. Dacre, M.R.C.V.S.,[A] after reading an article on the operation
before the members of the Lancashire Veterinary Medical Association, says:
'My observations have not been based on a single case, and having had nine
of them, and all of them successful, I felt it to be my duty to bring this
subject before the Society.'

[Footnote A: _Veterinary Record_, vol. v., p. 407.]

Mr. T.W. Thompson, M.R.C.V.S.,