THE ORGANS OF SPECIAL SENSE. 233 



should first be thoroughly washed with soft soap and 

 warm water, and any hair in the immediate neighbourhood 

 of the invaded parts cut off very close as by shaving ; the 

 scabs must be removed as carefully as possible, and the 

 coat should not be spared if any risk of diseased parts 

 being concealed by it be run. The smallest invaded part, 

 if untreated, will constitute a centre for fresh spread of 

 the disease and may cause a very considerable amount of 

 trouble subsequently ; the feet and ears should especially 

 be examined with care lest they remain imperfectly dressed. 

 It must be remembered in the selection of parasiticides 

 that the dog is constantly gnawing the affected parts and 

 also that the agents are liable to be absorbed through the 

 sores, therefore such medicaments as tobacco and mercurial 

 ointment, although very effectual as parasiticides, require 

 to be used with so great caution as to be practically inad- 

 missible, except for small patches of disease out of reach 

 of the mouth. Whether the application resorted to be a 

 lotion, oil, or ointment it must be applied with the greatest 

 assiduity, well and thoroughly rubbed in, and it will require 

 repetition at intervals not exceeding three days. Even 

 most severe and long-standing cases will at length succumb 

 to persistence ; thus Blaine " once occasioned a very 

 favourite setter who had had virulent mange for five years 

 to be dressed every day, or every other day, for the extra- 

 ordinary period of twelve months " before he could conquer 

 the disease. He estimates two hours at least as the time 

 required to dress a dog thoroughly, and when the job has 

 been neatly managed the dog will appear nearly as clean 

 as though nothing had been applied. He gives numerous 

 formulae for mange dressings, of which sulphur, turpentine, 

 tobacco, hellebore, and tar are the active ingredients, 

 aloes being added to prevent the dog licking them off, or 

 the animal carefully muzzled. Mercury compounds (the 

 nitrate, bichloride, and chlorinated salts) are advocated by 

 him in " red mange/' He gives the important practical 

 hint that a frequent change of applications will be attended 

 with benefit, and that the external dressings may be bene- 

 ficially supplemented by a course of tonics after the bowels 



