372 The Farmer's Veterinary Adviser. 



stance, as well as by the accumulation of crusts on the 

 surface. In j&ne skins, like that of the sheep, there is a 

 distinct papular eruption, and in all there are excoriations 

 and even deep sores and ulcers from the incessant and 

 desperate rubbing. The bare patches are less absolutely 

 BO than in ringworm, for hairs still adhere at intervals 

 and though the hairs may be broken they show less brit- 

 tleness or tendency to split up. But the one rehable sign 

 is the presence of the acarus, which may often be rec- 

 ognized by the naked eye when a little of the scurf ia 

 placed on a plate of glass and closely watched. The 

 scabs wiU. be seen to move and a Httle observation will 

 enable one to detect the almost invisible insect. A low 

 magnifying power is a great help. To find the sarcoptes 

 it may be necessary to expose the skin to the warm rays 

 of the sun, to detach a crust and tie it for twelve hours on 

 the skin of the arm, when the acarus will be found in the 

 centre of a pale red papule and may be removed with a 

 needle. 



The dermanyssus may not be found on the skin unless 

 the subject is examined in the stable at night. They are 

 large and easily detected when bright crimson, from being 

 gorged with blood. There is always the suspicious prox- 

 imity of chickens or their dimg, the latter swarming with 

 gray acari. 



The demodex living in the hair follicles of dogs, causes 

 loss of hair and prominent red nodules (acne) while the 

 sebaceous matter squeezed from the foUicles contain spec- 

 imens of the acarus. 



The sarcoptes of chickens attacks the comb, wattles and 

 feet, causing great irritation. 



Treatment is local, though nourishing food, cool clear 

 air, clean dry buildings, and the avoidance of crowding or 

 exertion are important auxiliaries. By soap-suds, pre- 

 ceded if necessary by oil, break up and remove the scabs 

 and crusts ; then apply thoroughly with a brush, oil of tai 

 I oz., whale-oil 20 oz., or ^ lb. each of tar and sulphur, 



