644 



SCABIES — SCAB — MANGE. 



DEMODECIC MANGE IN THE OX. 



This was described in 1845 by Gros, and in 1878 was found by Faxon 

 in Illinois in the skins of cows prepared for tanning. It has not been 

 met with in France. The skins examined by Faxon showed numerous 

 rounded enlargements, resulting from dilatation of the hair follicles in 

 the regions of the neck and shoulders. 



By pressing on these enlargements a whitish, greasy, sebaceous 

 material was ejected, very rich in demodectes. 



DEMODECIC MANGE IN THE GOAT. 



This was first noticed by Niederhaiisern, at the Bern Veterinary 

 College, in a goat which showed little nodosities over different parts of 



the trunk, varying in size between 

 that of a pea and that of a hazel- 

 nut. By forcibly compressing these 

 enlargements a yellowish-grey semi- 

 solid material, containing a consider- 

 able number of demodectes, was caused 

 to exude. 



In 1885 Nocard and Eailliet found 

 the same parasite in a young he- 

 goat ; the pustules were spread over 

 the sides and flank. Treatment con- 

 sists in opening the pustules and 

 dressing them a few times with an 

 antiparasitic lotion. 



Fig. 263. — Demodex of the pig, 

 magnified 250 diameters. (After 

 RaiUiet.) 



DEMODECIC MANGE IN THE PIG. 



This was well described for the 

 first time by Csokor. It was after- 

 wards seen by Neumann and Lindqvist. 

 . The isolated pustules are of the 



size of a grain of sand, but when confluent may reach the size of a 

 hazel-nut. They are sometimes dark in colour, often deep-seated, are 

 surrounded by a zone of inflammation, and appear in places where the 

 skin is fine (the groin, neck, belly, etc.). The demodex becomes lodged 

 and multiplies, not in the hair follicles, but in the sebaceous glands. 

 Csokor regarded this disease as contagious ; in a herd of one hundred 

 he found twenty-two pigs affected with it. Lindqvist, however, found 

 but one case in a herd of two hundred. 



