surgical skill.

_Causes._--Direct injuries to the coronet, such as trampling, pricks,
burns, and the blow of some heavy falling object which may puncture,
bruise, or crush the cartilage, are the common direct causes of
cartilaginous quittor. Besides being a sequel to the other forms of
quittor, it sometimes develops as a complication in suppurative corn,
canker, grease, laminitis, and punctured wounds of the foot. Animals
used for heavy draft, and those with flat feet and low heels, are more
liable to the disease than others, for the reason that they are more
exposed to injury. Rough roads also predispose to the disease by
increasing liability to injury.

_Symptoms._--When the disease commences as a primary inflammation of the
cartilage, lameness develops with the formation of a swelling on the
side of the coronet over the quarter. The severity of this lameness
depends largely upon the part of the cartilage which is diseased, for if
the disease is situated in that part of the cartilage nearest the heel,
where the surrounding tissues are soft and spongy, the lameness may be
very slight, especially if the patient is required to go no faster than
a walk; but when the middle and anterior parts of the cartilage are
diseased, the pain and consequent lameness are much greater, for the
tissues are less elastic and the coffin joint is more liable to become
affected.

Except in the cases to be noted hereafter, one or more fistulous
openings finally appear in the tumor on the coronet. These openings are
surrounded by a small mass of granulations which are elevated above the
adjacent skin and bleed readily if handled. A probe shows these
fistulous tracts to be more or less sinuous, but always leading to one
point--the gangrenous cartilage. When cartilaginous quittor happens as a
complication of suppurative corn, or from punctured wounds of the foot,
the fistulous tract may open alone at the point of injury on the sole.

The discharge in this form of quittor is generally thin, watery, and
contains pus enough to give it a pale-yellow color; it is offensive to
the sense of smell, due to the detachment of small flakes of cartilage
which have become gangrenous and are seen in the discharge as small,
greenish-colored particles. In old cases it is not unusual to find some
of the fistulous openings heal at the surface; this is followed by the
gradual collection of pus in the deeper parts, forming an abscess, which
in a short time open