6 The Sheep-Scab. 



tion the scab as a prevalent, infectious and mor- 

 tal disease among sheep. 



Until • a comparatively recent date, however, 

 the cause of the disease was not known. Youatt 

 in his work on the sheep, published in 1840, and 

 re-issued in a new edition in 1878, mentions that 

 the scab may be produced by a variety of causes, 

 such as bad keep, starvation, hasty driving, dog- 

 ging and exposure afterwards to cold and wet; 

 thus producing suppression of the perspiration. 

 At the same time he admits the presence of the 

 parasitic mite known to all who have been 

 troubled with this disease in their flocks. W. C. 

 Spooner, veterinary surgeon of Southampton, 

 England, when treating of sheep-scab, pertinently 

 stated that the scab is similar to the itch in 

 man and the fnange in dogs and horses, being in 

 fact, like these diseases, usually propagated by 

 contagion ; but he adds that ^^ poverty and filth 

 lu ill produce itP'' 



That the scab may or can be produced spon- 

 taneously, by poor keep or insufficient nourish- 

 ment, has never been established as a fact in the 



