390 DISEASES OF THE HOKSE. 



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 simple reason that they are 

 more exposed to injury. Eough roads also predispose to the disease 

 by increasing liability to injury. 



Symptoms. — When the disease commences as a primary inflamma- 

 tion of the cartilage, lameness develops with the formation of a swell- 

 ing on the side of the coronet over the quarter. The severity of this 

 lameness depends largely upon the part of the cartilage which is dis- 

 eased, for if the disease is situated in that part of the cartilage nearest 

 the heel, where the surrounding tissues are soft and spongy, the lame- 

 ness 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 tlie tissues are less elastic and the coffin joint is more 

 likely 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. "^AHien 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 enough pus 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 

 the corresponding quarter, owing to the stimulating effect which the 

 disease has upon the coronary band. 



Complications may arise by an extension of the disease to the lat- 

 eral ligament of the coffin joint, to the joint itself, to the plantar 

 cushion, and by caries of the coffin bone. 



Treatment. — Before recovery can take place all of the dead cartilage 

 must be removed. In rare instances this is effected by nature without 

 assistance. Usually, however, the disease does not tend to recovery, 

 and active curative measures must be adopted. The best and sim- 



