CHAPTER XIII. 
DISEASES OF THE EAR. 
CANKER (ExTERNAL), POLYPUS, 
CANKER (INTERNAL), DEAFNESS, 
SEROUS ABSCESS, ‘SCURFY EARS. 
. CANKER (EXTERNAL). 
‘THERE are few diseases which cause more trouble and 
annoyance, alike to owner and subject, than the one known 
as “canker.” All’ dogs are liable to this malady; but 
long-haired ones, and especially water- dogs, are those — 
usually affected. 
The disease is generally divided into external and in- 
ternal canker. External canker is that which attacks the 
edge or margin of the ear-flap. 
Internal is usually confined to the passage leading to the 
ear proper. 
Both forms are the same in character, and may co-exist 
or arise independently of each other. 
Causes.—Canker may be produced by external violence, 
gross feeding, over-heating food, plethora, uncleanliness. It 
is frequently associated with mange and eczema. 
Symptoms.—The first generally observed is repeated 
‘shaking of the head and flapping of the ears. Examination. 
reveals the integument covering those organs red, puffy, 
and hot, and this condition is aggravated by the animal 
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