382 DISEASES OF THE EAR. 



Sewell). The parasite which is common to the dog and cat is said 

 to produce a peculiar form of vertigo. 



The parasite differs from the common symbiot by the absence 

 of abdominal lobes in the male, which are represented by a notch 

 which has three bristles; the pubescent female has four pairs of 

 legs which are simple knobs. The male is 30 mm. long and 23 

 mm. wide, and the female is 42 mm. long and 29 mm. wide (Neu- 

 mann). 



Hering found this parasite in an ulcer of the ear which was 

 accompanied by a deep-seated otitis. Nocard describes minutely cer- 

 tain epileptiform fits in which the dog has a peculiar husky cry and 

 rushes about violently, running into various obstacles, and finally 

 falls insensible, and after a number of such attacks becomes totally 

 deaf. Sewell describes the condition as finding a collection of 

 brown or sooty-colored cerumen in the ear, or as looking dirty. 

 If the inside of the ear is examined closely a number of tiny white 

 specks, the size of the eye of a needle, are seen to be rapidly 

 moving about the ear, and he believes that the tickling sensation 

 caused by these movements and the biting of the parasite are what 

 produce the irritation of the lining membranes of the ear. 



Symptoms. The ear is hot and slightly swollen, and on (xam- 

 ination it is hardly distinguishable from ordinary otitis ; there is, 

 however, less discharge in this condition; the head is carried to one 

 side, and the animal will scratch the base of the ear very gently 

 with its paw and whine in a plaintive way. The translator has 

 observed a number of animals infected with the parasite, and is 

 inclined to think that the carrying of the head on one side and the 

 gentle scratching of the ear are characteristic of the disease, although 

 it is quite frequently seen in non-parasitic otitis. He has never 

 observed the epileptiform symptoms described by Nocard, although 

 he has made numerous examinations of animals that have presented 

 similar symptoms. 



Tkeatmext. Nocard recommends naphthol 1 part, ether 

 sulph. 3 parts, aud olive oil 10 parts. This should be injected 

 into the external auditory canal once daily, and the car plugged up 

 with cotton to prevent the escape of the ether. The translator 

 does not think the latter procedure advisable, for if the ether 

 is confined in the ear it causes great irritation, and has found from 

 experience where he has followed this procedure that while he may 



