416 DISEASES OF THE HORSE. 
rule, it attacks but one foot at a time, and but one of the cartilages, 
generally the inner one. It is always a serious affection for the 
reason that, in many cases, it can only be cured by a surgical opera- 
tion, requiring a thorough knowledge of the anatomy of the parts 
involved, and much surgical skill. 
Causes.—Direct injuries to the coronet, such as trampling, pricks, 
burns, and the blow of some heavy falling object which may punc- 
ture, 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. <Ani- 
mals 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 2 primary inflamma- 
tion 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 Jess sinuous, but always Jeading 
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 opens at a new point. The wall of the hoof, 
over the affected quarter and heel, in very old cases becomes rough 
and wrinkled like the horn of a ram, and generally it is thicker than 
