420 DISEASES OF THE HORSE. 
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 
painful. True, the treatment of canker is likely to exhaust the 
patience, and sometimes the resources, of the attendant; but after 
all suecess 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 
charcoal or a tablespoonful of the acid mixed with the poultice serves 
to destroy much of the offensive odor. The diseased portions of 
horn are 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 thin, 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; but it 
will be necessary to change frequently from one to another, until 
finally 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; chlorid of zinc, bichlorid of mercury, calomel, caustic 
soda, nitrate of silver, chlorid 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 from the bath it is dressed with oakum balls dipped in a 
mixture made of Barbados tar 1 part, oil of turpentine 8 parts, to 
which is 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 sufficiently 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 incased in a 
boot or folded gunny sack and the patient turned into a loose, 
