314 DISEASES OF THE HORSE'S FOOT 



Differential Diagnosis and Prognosis. — Perhaps the only 

 disease with which canker may be confounded is thrush. 

 They should, however, be easily distinguishable. The dis- 

 charge from thrush is not so profuse, and is thicker and 

 darker in colour, while the loosening of the horn is almost 

 entirely absent. Furthermore, thrush shows no tendency 

 to spread, and, even when left untreated, may remain 

 confined to the frog for months, and even years. Canker, 

 on the other hand, is slowly progressive, and soon shows 

 the characteristic fungoid excresences, which growths are in 

 thrush never seen. A further point of difference is dis- 

 covered when treatment is commenced. Canker is found 

 to be refractory to a point that is absolutely disheartening, 

 while thrush, with careful attention, is soon got under hand, 

 and a permanent cure effected. 



The prognosis must be guarded. By many canker has 

 been said to be incurable. This, however, has been clearly 

 shown to be wrong. When the animal is young, and treat- 

 ment may reasonably be judged to be economical, then a 

 favourable prognosis may be indulged in, provided the 

 veterinary surgeon intends to put into that treatment a 

 more than ordinary amount of individual care and atten- 

 dance. Even then, however, he will have to be very largely 

 guided by the condition of his case. He should see that it 

 is not too far advanced, and that a great deformity of the 

 hoof, or actual exploration, does not indicate disease of the 

 greater part of the wall. 



Treatment. — From what has gone before, it will be seen 

 that the eradication of canker is no easy task, that it is, 

 in fact, a more difficult matter, and one not to be lightly 

 undertaken. At the risk of recapitulating what we have 

 said before, we may mention here the two points which the 

 veterinarian must bear in mind. (1) That there is no 

 actual disease or alteration in structure of the deep layers 

 of the keratogenous apparatus. It is only the superficial, 

 or horn-secreting, layer that concerns us. (2) That the 

 disease of this superficial layer is infection with a material 

 that may reasonably be presumed to be infective. 



