Diseases of the Ear. 193 
cotton wool saturated with it and packed gently in. For 
internal canker, the zinc lotion, 5 grains to the ounce of 
water, applied three or four times a day, I find usually 
answers better than anything else. If raw spots or 
ulcerations are noted, the parts should be mopped with a 
solution of nitrate of silver, and this may be repeated every 
other day. In many cases after syringing with carbolised 
warm water (I—40), the parts may with benefit be dusted 
with the dry oxide of zinc. Equal parts of balsam of Peru 
and ox-gall, daily dropped into the ear, has also been found 
successful. When the disease extends to the bones of the 
ear, humanity dictates an end to the creature’s sufferings. 
In all cases of canker, whether external or internal, it is 
absolutely necessary, in order to ensure success and rapidity 
of cure, that the animal should be prevented as much as 
possible from flapping, scratching, or rubbing the ears. For 
this purpose a cap of wash-leather or stout calico (the 
latter is coolest) should be placed over the animal’s head 
and tied under the throat (Fig.21). It should be similar 
FIG. 21. 
DOG WITH CANKER CAP. 
in shape (with the exception of the ear portion) to a horse’s 
hood, and is kept much easier in position than the usual 
three-cornered one. 
