948 Scabies. 



ered with a cohesive layer of crusts and at the same time the 

 skill swells as a result of frequent rublnng, becoming cracked 

 and raw and increasing the swelling of the face. 



The disease is benign inasmuch as it soon heals under treat- 

 ment ; if, however, it is neglected, the severe swelling of the lips 

 may hinder the taking of food. Now and then the alTection may 

 l)e transmitted to man (Gerlach), and on the other hand inter- 

 mediate infection mav occur from niangv goats (AVallraff and 

 Eoloff). 



According to Koloff & Neumauii, sareoptes mites avoid only the skin tliat is 

 eovereil with oily wool, while in sheep with wool that is not fatty (Hungai-ian, 

 Neapolitan, fat-tailed sheep) they also settle on the trunk and may even spread over 

 the whole body; in this case only a few large, hard and armor-like crnsts form on 

 the skin. 



2. Dermatocoptic Scab. This form of scab is very fre- 

 quent as a flock disease and occurs exclusively on the parts of 

 the body which are thickly covered with wool, wdiere the mites 

 are well protected and have sufficient warmth so that they are 

 able to multiply rapidly. It begins usually in the inguinal re- 

 gion and on the back, spreading from here along the back to 

 the sides of the body; in rarer cases it establishes itself here 

 first; the skin in front of the chest and on the lower abdomen 

 is never attacked. 



At first one perceives unrest caused by itching, then rub- 

 bing and gnawing of the posterior half of the body; soon the 

 wool is loosened at isolated places and single locks of wool are 

 raised over the surface of the fleece. When the diseased places 

 are scratched or rul)bed with the hand the animals shoAv a feel- 

 ing of pleasure by stretching the head, moving the lips, nibbling 

 with the teeth, pressing against the scratching hand, movements 

 of the tail and scratching with the hind feet. The itching is 

 most severe in the warm summer time, after exercise, in the 

 barn and at night. 



On parting the wool one encounters lentil-sized yellow or 

 reddish nodules on the skin, perhaps also little serous and puru- 

 lent vesicles may be seen, which dry up together with their con- 

 tents and change to thin, fatty, yellowish scales. By the occur- 

 rence of fresh scales in the immediate neighborhood and the 

 increasing exudation, fatty yellowish crusts and scales grad- 

 ually form. With the further extension of the process the small 

 spots unite to form larger, irregularly-shaped surfaces, which 

 now become covered with very thick, yellow crusts. These mat 

 the wool and are lifted up by the growing hair. As a result 

 great tufts of wool are thus raised from the fleece, and the sur- 

 face of the fleece becomes uneven; larger or smaller bunches 

 of wool may fall out, whereupon bald surfaces arise on the 

 body, especially along the line of the back, which are now cov- 

 ered with dry scabs. The skin then appears thickened, stiff 

 and cracked in places. In shorn sheep the crusts are dry and 

 brown in color on account of plentiful evaporation (Fig. 144). 



