194 "^^^ HORSB. 



rounding parts it dries and forms small cheesy masses composed of tlie 

 partly dried horny matter, exceedingly offensive to the sense of smell. 

 When the disease originates independently of an injury, the first evi- 

 dences of the trouble are the offensive odors of the foot, the liquid secre- 

 tion 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 local 

 motion, 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 production 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 stripping 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 speedily with measures which are less heroic and much less pain- 

 ful. True, the treatment of canker is likely to exhaust the patience, 

 and sometimes the resources, of the attendant; but after all success de- 

 pends more on the persistent application of simple remedies and great 

 cleanliness than on the special virtues of any particular drug. 



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

 taining powdered charcoal or carbolic acid. A handful of the charcoal, 

 or a table-spoonful of the acid, mixed with the poultice serves to destroy 

 much of the offensive odor. The diseased portions of horn now to be 

 carefully removed with sharp instruments, until only healthy horn bor- 

 ders the affected parts. The edges of the sound horn are to be pared 

 thin, so that the swollen soft tissues may overlap their borders. With 

 sharp scissors cut off all the prominent points on the soft tissues, shorten 

 the walls of the foot, and nail on a broad, plain shoe. The foot is now 

 ready for the dressings, and any of the many stimulating and drying 

 remedies may be used. Whichever is selected at the outset, it will be 

 necessary to change frequently from one to another, until all may be tried. 



The list from which a selection may be made comprises wood tar, gas 

 tar, petroleum, creosote, phenic acid, sulphates of iron, copper and zinc, 

 chloride of zinc, bichloride of mercury, calomel, caustic soda, nitrate of 

 silver, chloride of lime, carbolic, nitric, and sulphuric acids. 



