381 



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

 motion, but later the foot becomes sensitive, particnlarly if tiie auima- 

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

 destroyed the lameness is severe. 



Treat)nent. — 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 tlie 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, witli cither 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 

 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 special virtues of any particular drug. 



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

 containing powdered charcoal or carbolic acid. A handful of the char- 

 coal, or a tablespoonful of the acid, mixed with the poultice serves to 

 destroy much of the offensive odor. The diseased portions of horn are 

 now to be carefully removed with sharp instruments, until only healthy 

 horn borders the affected parts. The edges of the sound horn are to 

 be pared thiu, so that the swollen soft tissues may not 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 finally all may be tried. 



The list from which a selection ma\' 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. 



In practice I prefer to give the newly shod foot a bath for an hour or 

 two in a solution of the sulphate of iron, made by adding 2 ounces of the 

 powdered sulphate to a gallon of cold water. When the foot is removed 

 it is dressed with oakum balls, dipped in a mixture made of liarbadoes 

 tar, 1 part ; oil of turpentine, 8 parts, to which are slowly added 2 parts 

 of sulphuric acid, and the mixture well stirred and cooled. The diseased 

 parts being well covered with the balls, a pad of oakum, sufhciently 

 thick to cause considerable pressure, is placed over them, and all are 

 held in place by pieces of heavy tin fitted to slip under the shoe. The 

 whole foot is now encased in a boot or folded gunny sack, and the patient 

 turned into a loose, dry box. The dressings are to be changed daily, or 

 even twice a day, at first. When they are removed all pieces of new 



