CANKER. 187 



does not abate, the chloride of zinc lotion should be 

 tried. 



When either fever in the feet or navicular disease 

 gives rise to thrush, the cleft of the frog must be left 

 free, and the exciting causes treated as recommended 

 hereafter. A horse with a thrush should not be ridden 

 without knee-caps ; for if he bruise the frog, he will 

 generally fall and cut his knees severely. 



CANKER. 



Canker consists in ulceration of the sensitive frog, in- 

 volving the sole very frequently. It is the result of severe 

 constitutional derangement, such as a severe thrush, 

 cracked heels, or grease, and is most common amongst 

 cart horses, whose feet are never properly cleaned and 

 attended to ; and are generally allowed to stand for 

 days and weeks on litter saturated with urine, which, 

 by continuing the irritation during an attack of thrush, 

 results in canker being established. Any inflammatory 

 attack in the feet will produce this disease ; but it must 

 be considered as a secondary and not as a primary dis- 

 ease in general practice. 



The discharge will be usually thin and very offensive, 

 and the horn of the sole will break away and separate, 

 when the extent of the mischief may be readily ascer- 

 tained. 



I had to treat a very severe case of canker, a few 

 years ago, and after four months of careful treatment 



