378 DISEASES OF THE EAR. 



with a blackish loose scab with turned-up edges, and the tissues 

 of the immediate neighborhood are cedematous. 



Therapeutic Treatment. There is no doubt that the 

 quickest results may be obtained by cutting off a portion of the 

 diseased lobe of the ear; this, however, disfigures the animal very 

 much. This is the easiest method of cure, and the operation 

 is generally performed on animals under the influence of ether. 

 First remove the hair and thoroughly disinfect the parts, and 

 cut off a circular piece from the ear that will include the torn 

 portion, being careful not to remove any more of the lobe than is 

 actually necessary. Another method is to cut out of the edges of 

 the slit ear a thin section about one-eighth of an inch in thickness, 

 so as to insure two raw fresh surfaces; the two edges of the wound 

 must then be drawn together by means of sutures; these should 

 not be inserted too close to the edge of the wound, as they are apt 

 to tear through. The stitched line is then powdered with iodo- 

 form or sulphonal. The external ear is covered with wadding, 

 turned over the top of the head, and held in position by means 

 of a bandage, as indicated on page 376 (Fig. 83). 



If the animal is one that you cannot see and dress the part eve ry 

 day, instead of sewing the' wound after the lobe has been cut, 

 touch it up by means of the thermo-cautery, and by means of the 

 consequent cicatricial contraction draw the edges together. 



Hoffmann deviates from the above-described method, which was 

 practised by Siedamgrotzky, by using cocaine and cutting a three- 

 cornered piece out of the external integument, then stitching it 

 together without any attempt to control the hemorrhage. The 

 author has been able to obtain satisfactory results in slight cases 

 of external ear-canker by covering the ulcer with oxide of mer- 

 cury and tying the ear up. On the other hand, he was much dis- 

 appointed by caustics, such as acids, nitrate of silver, and corrosive 

 sublimate, as they gave only negative results. 



Inflammation of the External Ear — Internal Canker. 



{Otitis Externa.) 



This consists of an inflammatory irritation of the external canal 

 of the ear. It is generally of an eczematous nature and appears 

 in a diffuse form, extending over a larger part of the lining of the 

 ear. It is accompanied by redness, swelling of the membrane, 



