132 CANINE MEDICINE AND SURGERY 



the Elizabethan collar, from scratching or rubbing 

 the parts. 



Catarrh of the Auditory Canal 

 (Canker) 



Causes. — Dust, dirt, and water getting into the ear, 

 either during swimming or while the dog is being- 

 bathed, and the ear not being afterwards properly 

 dried, are a frequent cause of catarrh of the audi- 

 tory canal. . Parasites, the symbiotes auricularis var. 

 canis, are a not uncommon cause of the trouble. 



Symptoms. — The patient shows great irritation by 

 scratching, rubbing, and holding the head with the 

 affected ear downward, and pain is manifested by 

 the cries and yelps which accompany any manipu- 

 lation of the ear. Upon closer examination, caked 

 around the external auditory meatus and matting 

 the hair surrounding it, a brownish, sticky discharge 

 with a characteristic odor is noticed. If the base 

 of the ear is gently pressed a sucking sound is 

 heard and the patient evinces pain. In parasitic 

 canker the parasites may be discovered by a care- 

 ful examination with a magnifying glass. In excep- 

 tionally severe and long-standing cases the middle 

 and internal ears may become involved, deafness and 

 sometimes fatal meningitis being the results. 



Treatment. — The patient should be secured on the 

 operating table in the abdominal position and muz- 

 zled to prevent accidents. The ear should then be 

 thoroughly but gently cleaned with hydrogen peroxid 

 and absorbent cotton swabs. It is essential that the 

 whole of the external ear, comprising ear flap, ex- 

 ternal auditory meatus, and auditory canal, be cleared 

 of every vestige of discharge at the first treatment. 

 The ear and canal should then be thoroughly dried 

 and the canal filled up with either of the following 

 dusting powders: Chinosol (fifteen grains), or for- 



