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DISEASES OF THE EAR 



Ulceration of the External Concha. — External Canker. 



By this we mean a purulent or ulcerative process on the edge of the 

 external ear. This, however, is not contined to the edge, but may spread 

 over different parts of the lobe. 



Etiology. — The chief causes of this trouble are injuries and lacerations 

 of the skin. Dogs are liable to scratch or shake the ears violently against 

 the muzzle or collar, producing an inflammation. It may also be devel- 

 oped from the ear itself, as in cutaneous inflammations of the external 



Fig. 154. — Mode of bandaging the ear. 



auditory passages. We may also see this as a re.sult of wounds or lacera- 

 tions of the ear caused by bites of other dogs, which from neglect or 

 improper treatment become ulcerated and do not heal readily on account 

 of constant shaking of the ear. This affection is almost entirely confined 

 to animals with long ears and short hair. 



Clinical Symptoms. — The animals hold their heads to one side, 

 shaking the ear frequently, sometimes keeping it up so long that the 

 ulcerated surface bleeds and the blood is thrown in all directions. They 

 attempt to scratch the affected ear with their paws, and are very sensitive 

 about having them touched. On makinu- an examination we find at the 



