Symptoms. 



973 



the affected parts of the body swell visibly. Then the animal 

 falls away greatly in condition, gives oft" a very objectionable 

 smell, and finally dies, completely exhausted, as a result of in- 

 toxication or general septic infection. 



In mauy cases the disease extends over the whole body, the neck appears 

 covered with bran-like scales, and scattered single pustules may be present, yet 

 the hair falls out only in isolated circumscribed places and the skin here shows 

 the appearance of moist eczema. 



Horneck found the mites in the secretions from the eyes, ear and prepuce 

 of dogs affected with acariasis. 



In cats the hair follicle mites very rarely cause disturbances. 

 The head, round about the eyes, nose and ears are spots of 

 predilection of the disease, which causes similar changes as in 

 the dog, although at times 

 they are transitory and 

 not very pronounced. 

 Sometimes the hair folli- 

 cle mites are encountered 

 in the external ear pas- 

 sage w i t h o u t h a V i n g 

 caused any s\anptoms of 

 disease (Hyrtl, Megnin). 



In pigs the disease as- 

 sumes a similar form to 

 that in the dog, only that 

 here the mites live in the 

 sebaceous glands, and be- 

 sides purulent vesicles are 

 formed through coales- 

 cence of pustules, which 

 are as large as a hazel- 

 nut and may contain 1,000 

 mites; after breaking up 

 they may lead to ulcer- 

 ation without any ten- 

 dency to healing. Now and 

 then, however, only millet- 

 sized to lentil-sized com- 

 edo-like nodules appear in the skin, from which a soft pulpy 

 mass can be expressed (Knoll). These changes are generally 

 found on thin-skinned spots (around the snout, cheeks,^ fore- 

 head, lateral surfaces of the neck and body, lower belly, in the 

 folds of the stifle, inner surfaces of the thighs), while the back 

 of the neck, the back and the external surface of the thighs al- 

 most always remain healthy, even in severe cases. According 

 to Eieck, isolated pustules not infrequently occur in the folds 

 of the stifle. In a case described by Miiller the skin of the legs 

 of a pig had the appearance of pearl beading. 



In European cattle acariasis is very rare, but may, in large 

 herds, attain the form of an enzootic, as the observation of 



Fig. 156. Acariasis in the clog. Folds and 



thickening of the skin on the head and fore 



legs. 



