Diseases Affecting the Skin and Ears 225 



transmitting the rays of light from the retina to the 

 nerve centre. The best evidence of amaurosis is 

 afforded by the pupil of the eye, which remains 

 widely dilated in a strong light. The causes of this 

 eye trouble are variable, sometimes resulting from 

 injury, which induces pressure upon the optic nerve. 

 Excessive bleeding is sometimes a cause. 



Diseases affecting the Skin and Ears 



The cutaneous affections of the dog are fairly 

 numerous, but, what is still a worse feature, many 

 of these are extremely troublesome, demanding the 

 exercise of patience, perseverance, and a reasonable 

 amount of skill for their successful treatment. 

 Some skin affections are so closely allied in their 

 clinical features that it not only requires considerable 

 experience, but also the use of the microscope for 

 their satisfactory demonstration. All those who 

 keep hounds, no matter individually or as a pack, 

 are well enough aware of the troublesome nature of 

 many skin diseases. This is partly accountable for 

 through errors in diagnosis of the disease, conse- 

 quently the results are often very unsatisfactory. 

 Let us take, for instance, parasitic mange, the early 

 diagnosis of which is of vital importance, otherwise 

 the disease may spread throughout the whole kennel. 

 Popular terms for skin diseases in the dog are, 



