DISEASES OF HORSES AND CATTLE. 267 



the legs and bulbs of the heels are injured we find 

 a growth resembling canker developing. 



Causes: It is said by some to be caused by a 

 vegetable parasite, but I do not think such is the 

 case; the vegetable parasite is the result, not the 

 cause. I have removed the horny frog and bound 

 on the exudation from a canker, but could not 

 produce it. It is said from some unknown rea- 

 son horses with lymphatic temperaments, thick 

 skin, flat feet, fleshy frogs, heavy hair, and particu- 

 larly white feet and legs are especially liable to 

 canker. The tissue of such horses is soft and low 

 organized, and when injured is not so easily healed 

 as that of a well-bred horse, and has more tenden- 

 cy to take on an unhealthy development. I think 

 that is likely the reason why the heavy draft horse 

 is more liable to such derangements. It is said the 

 is likely the- reason why the heavy draft horse is 

 more liable to such derangements. It is said the 

 condition most favorable for the development of 

 canker is dampness; in fact, dampness seems to 

 be indispensable to the existence and growth of 

 the parasite. I have no doubt that such is the 

 case so far as the parasite is concerned, but as for 

 canker the majority of cases that have come under 

 my notice have been horses which worked in the 

 city, having good, comfortable, dry stables. I 

 cannot recall a case which I consider was caused 

 by dampness. The worst case of canker I ever had 

 to treat was during the summer months, when 

 everything was excessively dry and the stable was 

 kept clean. Canker seems to be a disease peculiar 



