hin the hoof,
breaks out at the coronet. Again, too, as with the simpler form of quittor,
and as with coronitis, we may always regard as a predisposing cause the
action of excessive cold in promoting septic infection of the wound when
occurring at the coronet.

_Symptoms and Diagnosis_.--Where the fistulous wound has had its
starting-point in an injury to the coronet diagnosis is, of course, easy.
The history of the case explains it. Nothing in this instance remains but
to probe the opening, and ascertain its direction, depth, and extent.

An animal with the wound thus open at the coronet, and freely discharging
its contents, may, if no serious complications exist, walk tolerably sound.
It is only when put to the trot that symptoms of lameness are apparent.

It may so happen, however, that we first see the case when the symptoms are
wholly those arising from a painful suppuration within the horny box.
This occurs when the original injury has taken place at a more dependent
position than the coronet. Either from violent blows upon the hoof,
puncture from below, from corn or from sand-crack, or any other causes we
have enumerated, suppuration is occurring deeply within the hoof, with as
yet no opening upon the coronet.

Even when an opening has already occurred on the coronet, the same
condition of sub-horny suppuration may be met with in cases when the
opening of the fistula has by some means or other become occluded.
Granulation tissue, for instance, may have temporarily closed the mouth of
the fistula. The pus, instead of continuing its discharge thereat, is made
to burrow in other directions.

In either of these cases pain is excessive, the animal walks on three legs,
the foot is painful to percussion, and grave constitutional disturbance
is noticeable. The presence of pus is immediately suspected, and, in the
absence of any indication of an opening having existed at the coronet,
searched for at the sole. It may or may not be found. If found it is given
exit, and the case ends as one of ordinary pricked foot, of suppurating
corn, or some other condition equally simple when compared with quittor.
In those cases where the pus is not discovered at the sole, one adopts the
expectant treatment of poulticing. This, if pus is present, is followed
by a painful swelling of the coronet. At one point there forms a hot and
tender enlargement, with the hairs on it standing straight up from the
skin, which latter is seen below