240 VETEEINAKY MEDICINE AND SUKGERY. 



CANKER. 



Definition. — Canker is a morbid secretion of the sensitive frog and 

 sole, involving, of course, the corresponding insensitive parts. 



Etiology. — This formidable disease usually has its origin in neglected 

 thrush, but it may be due to constitutional causes. It is not common in 

 this country. 



Symptoms. — Williams says: The characteristic symptoms of the 

 disease are strongly marked, and consist of an abundant foetid, colorless 

 discharge from the frog, which is large, spongy, and covered by pallid, 

 stringy prominences of a fungoid nature, intermixed with offensive 

 smelling, semi-dried, cheesy masses of matter, composed of imperfect 

 horn cells. 



It seems as if the various constituents of the horn were in an uncom- 

 bined state; the sulphur, which is a natural constituent, being secreted 

 as sulphuretted hydrogen, giving the characteristic foetor to the whole 

 secreted mass; horny matter imperfect, and floating in an abun- 

 dant liquid material; the secreting villi enlarged, scantily covered by a 

 thin pellicle of horn, giving them superficially a v/hite appearance, whilst 

 underneath they are turgid, congested, and humid. 



Treatment. — The treatment of canker consists in the complete ex- 

 posure of the diseased surface, in the application of pressure, and in 

 thorough dryness. 



The whole, not merely the diseased portion, but the whole of the in- 

 sensitive sole, must be removed. When this has been thoroughly and effec- 

 tively done, the whole of the exposed surface must be dressed with nitric 

 acid. The sole must then be firmly packed with dry tow, secured with 

 a bandage, and the foot inclosed in a leathern boot. This will give 

 the necessary pressure. To prevent excessive bleeding, from the removal 

 of the sole, a tourniquet should be applied to the fetlock. The foot, 

 bedding, and stall must be kept scrupulously dry. 



After two days the dressing should be removed. In favorable cases, 

 the whole of the exposed surface of the foot will present a healthy apj^ear- 

 ance, and will gradually become covered with good horn, and no further 

 treatment will be required beyond cleanliness, dryness, mild astringents, 

 and moderately firm pressure and bandages. For at least a week after 

 the ojieration, the horse should stand without shoes. But as soon as the 



