Psoroptic Acuriasis in Sheep. 183 



variable feeding — rich and poor, — or good or bad general health, 

 so that they must not be looked on as peculiar to scabies. They 

 greatly reduce the value of the fleece for weaving, and at the 

 Gobelins manufactory they seriously interfered with uniform and 

 perfect dyeing (Delafond). 



As in all cases of the violent local irritation and infection the 

 subjacent lymph glands may become enlarged and tender, and 

 suppurating and septic foci may form in distant organs. 



Left to itself the disease tends to constant advance, with en- 

 creasing emaciation and debility, and leading to marasmus and 

 death. It makes less progress in the open summer pasture than 

 in close, warm buildings, but more in the very young or in ani- 

 mals that are emaciated and weak than in those that are in the 

 prime of life, and in the fine-wooled than in the long-wooled. In 

 exceptional cases, it is claimed that long-wooled sheep, in middle 

 age, and in high condition, on rich pastures will get well spon- 

 taneously, but in any case they respond much more readily to 

 judicious treatment than do others. This tendency of the disease 

 to stand still or even abate somewhat when at pasturage, accounts 

 somewhat for the partial or complete neglect of scabby sheep kept 

 on open ranges and rarely or never shut up indoors. 



Diagnosis must usually rest on the inveterate itching, the seat 

 of the affection (neck, back, loins, croup, etc.), the accumulation 

 of debris in the deeper layers of wool, and finally on the discovery 

 of the acarus. By raising the scabs from among the wool around 

 the margins of the bare spots, and placing them on black paper or 

 on a glass slide in the sunshine or in a warm room, their presence 

 is quickly manifested by a movement of the scabs, and the acarus 

 can be detected with the aid of a hand lens, or a low power of the 

 microscope. 



Treatment. One of the first considerations is to sustain or 

 improve the general health, and keep the patient as far as pos- 

 sible in the open air. A rich succulent pasture is to be furnished 

 when possible. When this is impracticable as in the winter sea- 

 son, a comfortable, roomy, airy shelter, with ample space to run 

 in the sunshine is desirable. No less .so is nourishing food to 

 obviate that low health or debility which so much conduces to the 

 multiplication of the psoroptes and the sinking of the sheep below 

 the standard of successful resistance. 



