CANKER. 447 



tion of the membrane or skin lining the ear. This produces irri- 

 tation, and the dog shakes his head continually, which, together 

 with the tendency to spread externally, causes an ulceration of the 

 tips of the ears of those dogs, such as the hound, pointer, setter, 

 spaniel, &c, which have these organs long and pendulous. Hence 

 the superficial observer is apt to confine his observation to this 

 external ulceration, and I have even known the tips of the ears 

 cut off in the hope of getting rid of the mischief, whereas it was 

 only aggravated, because the incessant shaking caused the wound 

 to extend, while the internal mischief was not in the slightest 

 degree relieved. The pointer is particularly liable to " canker," 

 as shown on the tips of the ears, because he has little hair on this 

 part to take off the acuteness of the " smack " which is given in 

 the shaking of the head. Long-haired dogs, on the other hand, 

 are quite as liable to the real disease, as evidenced on an examina- 

 tion of the internal surface, but, from the protection afforded by 

 the hair, the pendulous ear is not so much ulcerated or inflamed. 

 Whenever, therefore, a dog is. seen to be continually shaking his 

 head, and abortively trying to rub or scratch his ear, not being 

 able to succeed because he cannot reach the interior, an examina- 

 tion should be made of the passage leading into the head ; and if 

 the lining is red and inflamed, there is clear evidence of the dis- 

 ease, even if the external ear is altogether free from it. On the 

 other hand, the mere existence of an ulceration on th$ tips of the 

 ears is no absolute proof of " canker," because it may have been 

 caused by the briars and thorns which a spaniel or hound has to 

 pass through in hunting for his game. Still it should lead to a 

 careful inspection, and, if it continues for any length of time, it 

 may be generally concluded that there is an internal cause for it. 

 The treatment should in every case be chiefly directed to the 

 internal passage, the cap which is sometimes ordered to be applied 



