ULCERS AND FISTTJLiE. 



303 



treatment is not to be depended upon, and it is better to use the knife 

 freely. 



When poll-evil is caused by the bearing-rein, it is deep-seated, perhaps 

 involving the synovial membrane of the occipito-atloidean articulation, 

 and some cases have terminated in anchylosis of this joint, causing the 

 animal to be permanently stiff-necked. In some instances the ulcerative 

 process has penetrated the capsules of the first or second cervical articu- 

 lations, causing sudden death by pressure upon the medulla spinalis; in 

 others, pieces of the bones become detached, keeping up the irritation 

 and formation of pus; these must be searched for and carefully re- 

 moved. 



FISTULOUS WITHERS. 



Fistulous withers are similar in their nature and require much th 

 same treatment as poll evil. They are nearly always caused by pressure 

 from the saddle, or collar, or by injuries. 



In most cases the mischief is at first very slight, and a day or two's 

 abstinence from work with a little alteration of the saddle or collar will 



Fig. 137. 

 Fistulous Withers. 



generally effect a cure and prevent recurrence. If the skin is tender, a 

 salt and water dressing may be applied. 



When, however, the cause is continued or repeated, the tissues under 

 the skin become inflamed, and the cartilaginous pads of the heads of the 

 spines of the vertebrae may be injured. If such should be the case, 



