DISEASES OF THE EAR, 187 



CANKER (Internal). 



Internal canker is most generally seen in water dogs. Youatt 

 observes : " When the whole of the body except the head and 

 ears is surrounded by cold water, there will be an unsual 

 determination of blood to those parts, and consequent disten- 

 sion of the vessels, and a predisposition to inflammation." 

 With this author I quite agree. 



Again, water being continually lodged in the ear, and re- 

 maining there, is in itself a source of irritation, and calculated 

 to produce canker. Allowing dirty suds to remain, after 

 washing, is an especially fruitful cause both of canker and 

 deafness. 



Internal canker, if neglected, is very much more disastrous 

 than the external form. The disease will extend to the in- 

 ternal bones of the ear, and cause the most maddening pain. 

 Or it may, and often does, without these ravages, result in 

 deafness, in which case treatment for the latter is generally 

 hopeless. 



Symptoms. — The membrane lining the passage, as far as 

 can be seen, is red and inflamed, and the root of the flap, hot 

 and tender. There is the same disposition to shake the head 

 and scratch the ears as in the external canker. As the 

 disease proceeds, an offensive, dark-colored discharge issues 

 from the passage of the ear, the itching becomes intolerable, 

 and the animal in his misery rolls about, rubs his ears along 

 the ground, frantically scratches at them, and utters pitiful 

 cries. 



Treatment. — This is of the same character as that pre- 

 scribed for the former, only differing in its mode of applica- 

 tion. The ear should be syringed (not too powerfully) with 

 warm water, and whatever lotions are used must be poured 

 into the ear, applied with a feather, or some 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 any 



