393 



Symptoms. — Usually, canker is confined to one foot; but it may 

 attack two, three, or all of the feet at once; or, as is more commonly- 

 seen, the disease attacks first one then another, until all may have 

 been successively affected. When the disease follows an injury which 

 has exposed the soft tissues of the foot the wound shows no tendency 

 to heal, but, instead, there is secreted from the inflamed parts a pro- 

 fuse, thin, fetid, watery discharge, which graduallj^ undermines and 

 destroys the surrounding horn, until eventually a large part of the 

 sole and frog is diseased. The living tissues are swollen, dark-col- 

 ored, and covered at certain i^oints with particles of new, soft, yellow- 

 ish, thready horn, which are constantly undergoing maceration in the 

 abundant liquid secretion l)y which thej^ are immersed. As this secre- 

 tion escapes to the surrounding i^arts it dries and forms small cheesy 

 masses composed of the partly dried horny matter, exceedingly offen- 

 sive to the sense of smell. When the disease originates independ- 

 ently of an injury, the first evidences of the trouble are the offensive 

 odor of the foot, the liquid secretion from the cleft and sides of the 

 frog, and the rotting away of the horn of the frog and sole. 



In the earlier stages of the disease there is no interference with 

 locomotion, but later the foot becomes sensitive, particularly if the 

 animal is used on rough roads, and, finally, when the sole and frog 

 are largely destroyed the lameness is severe. 



Treatment. — Since canker does not destroy the power of the tissues 

 to produce horn, but rather excites them to an excessive ijroduction 

 of an imperfect horn, the indications for treatment are to restore the 

 parts to a normal condition, when healthy horn may again be secreted. 

 In my experience, limited though it has been, the old practice of strip- 

 ping off the entire sole and deep cauterization, with either the hot 

 iron or strong acids, is not attended with uniformly good results. 



I am of the opinion that recovery can generally be effected as surely 

 and as speedil}- with measures which are less heroic and much less 

 painful. True, the treatment of canker is likely to exhaust the 

 patience, and sometimes the resources, of the attendant; but after 

 all success depends more on the persistent application of simple 

 remedies and great cleanliness than on the si^ecial virtues of any 

 particular drug. 



First, then, clean the foot with warm baths and, apply a poultice 

 containing j)owdered charcoal or carbolic acid. A handful of the 

 charcoal, or a tablespoonful of the acid, mixed with the poultice 

 serves to destroy much of the offensive odor. The diseased jiortions 

 of horn are now to be carefully removed with sharp instruments, 

 until only healthy horn borders the affected i^arts. The edges of the 

 sound horn are to be i)ared thin, so that the swollen soft tissues may 

 not overlap their borders. With sharp scissors cut off all the promi- 

 nent points on the soft tissues, shorten the walls of the foot, and nail 

 59(31— HOR 1.3* 



