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SHEEP-SCAB.* 



Sheep-Scab in this country is a purely contagious disease, 

 affecting the woolly parts of the body, and due to the 

 presence on the skin of a species of mite or acarus called 

 Dermatodectis ovis, but sometimes Posoroptis communis. 



Parasites very similar in form and size are also found on 

 the horse, dog, and other animals, producing the disease 

 commonly called mange, but the mange acarus of the horse, 

 dog, or other animals does not produce Sheep-Scab. It may 

 therefore be accepted that where sheep become affected with 

 Sheep-Scab they must have previously been in contact with 

 diseased sheep, or with tufts of wool left by diseased animals 

 on fences, posts, hurdles, or other objects against which the 

 animals have rubbed. 



Although the usual symptoms of Sheep-Scab are known to 

 most flock masters and shepherds, a description of them may 

 be given here. 



One of the first symptoms apparent in a sheep that has 

 contracted scab is restlessness on the part of the animal, and 

 a desire to bite the infected part or to rub against posts, 

 fences, hurdles, or other members of the flock. This restless- 

 ness is the result of the irritation and itching produced by the 

 mites pricking the skin of the sheep in their endeavour to 

 obtain food, and as they increase in number the constant 

 biting and rubbing of the sheep to allay the irritation causes 



*Copies of this article may be obtained separately (Leaflet No. 61), free of charge, 

 upon application to the Secretary, Board of Agriculture, 4, Whitehall Place, S.W. 



