112 PARASITES OF THE DOMESTIC ANIMALS 



the quarters in which they are collected are damp and hot. In summer, 

 after shearing and turning upon pasture, it rapidly subsides, in some 

 cases even seeming to disappear. 



Psoroptic scabies in sheep, if unchecked, will have a fatal termination. 

 Death is preceded by denudation of the greater part of the body, emacia- 

 tion, anaemia, and a progressive weakness. The course is often rapid 

 in stabled sheep and those predisposed; within one or two months it 

 may have spread over the greater part of the body, while, on the other 

 hand, the disease may last in a more or less severe form for a year or 

 more. 



Transmission. — Sheep scab cannot be transmitted to other animals, 

 nor caii psoroptic scabies of other animals be transmitted to sheep. 



Sarcoptic Mange of Sheep. — Sheep are rarely affected with this 

 form. When it occurs it can at once be distinguished from psoroptic 

 scab by its location, which is exclusively upon parts of the body covered 

 with short hair. It usually has its beginning about the upper lip or 

 nostrils, extending from here to other parts of the face and to the eye- 

 lids and ears. In cases of long standing it may spread to the belly and 

 inner sides of the front and hind legs. 



Prognosis. — The course of the disease with its typical skin altera- 

 tions has already been described under Sarcoptic Mange of the horse. 

 It is much less serious in sheep than in the horse, however, and if taken 

 before it has spread extensively, yields easily to treatment. 



Transmission. — Sheep and goats transmit sarcoptic mange recipro- 

 cally. It has been reported as having been conveyed from these animals 

 to man, but such cases, if ever occurring authentically, should be ex- 

 tremely rare. 



Chorioptic Scabies of Sheep. — As in the horse, chorioptic scabies of 

 the sheep begins in the hind fetlocks and pasterns where it is charac- 

 terized by a redness of the skin and the presence of fine epidermic scales. 

 There is considerable itching, causing the animals to stamp their feet 

 and bite at the infected parts. Later yellowish crusts appear which 

 thicken, and the skin becomes cracked and bleeding, especially about 

 the folds of the pastern. Only rarely does the affection pass to the fore 

 legs or upward to the udder in the ewe, or to the scrotum in the ram. 



Prognosis and Transmission. — Again, as in the horse, the Chorioptes 

 are not inclined to migrate, and the scabies they produce is but shghtly 

 contagious. It yields promptly to cleanliness and proper treatment, 

 subsiding almost entirely when the flock is turned upon grass in the 

 spring. 



Follicular Mange of Sheep. — The follicular mite occasionally in- 

 vades the eyelids of sheep. Few such cases have been recorded, however, 

 and, in this country at least, follicular mange is of little importance to 

 flock owners. 



