EXTERNAL CANKER. 377 



3. The third method, which is generally the most successful, 

 provided it is performed under antiseptic rules, is as follows : 



Shave and thoroughly disinfect the lobe. A long incision in 

 a longitudinal direction of the ear must be made, and the clots 

 and remains of tissue removed. The cartilage must be scraped 

 carefully, so that we see a fresh wound surface. Sew it up with 

 catgut ligatures, keeping as close as possible to the cartilaginous 

 surface. Place the drainage-tube in the ear, turn the ear up on 

 the top of the head and dress it with antiseptic cotton. Examine 

 the dressing every day to be certain that it is in its proper place. 

 This, as a rule, cures the wound entirely in from three to six days, 

 provided that the antiseptic rules are followed very carefully; but 

 it is generally advisable to leave the dressing stay on from eight 

 to ten days, as the union between the two surfaces is not strong 

 enough to stand the energetic shaking of the head which every 

 dog does for some time after the removal of an ear bandage which 

 has been on for several days. 



External Canker. 



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

 of the external ear. This, however, is not confined 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 inflam- 

 mation. It may also be developed from the ear itself, as in cuta- 

 neous inflammations of the external auditory passages. We may 

 also see this as a result of wounds or lacerations 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. 



Clinical Symptoms. The animals hold their heads to one 

 side, shaking the ear frequently, sometimes keeping it up so lono- 

 that the ulcerated surface bleeds and the blood is thrown in all di- 

 rections. They attempt to scratch the affected ear with their paws, 

 and are very sensitive about having them touched. On making 

 an examination we find at the edge of the external ear, generally 

 its extreme end, an ulcer or a number of them which are covered 



