SHEEP SCAB. 7 



driven, as itching is more intense when they are heated. They bite 

 and scratch themselves and rub against any available object, includ- 

 ing other members of the flock. The natural position of the wool is 

 disturbed by these efforts to obtain relief, and as more or less wool 

 is pulled out, the fleece assumes the condition known as " broken." 

 At first the wool on the affected parts, if within reach of the mouth, 

 is seen to have been chewed and some of it pulled out. The w^ool on 

 affected parts not within reach of the mouth has a discolored, worn, 

 or ragged ap]:)earance, caused by scratching with the hind feet or 



First break in fleoco, early stages of scab, losions alwut the sizi^ of a pea. 



rubbing against other objects. At this stage the marks of the mouth 

 or feet on the fleece or the disturbed position of the wool may be the 

 only visible symptoms, unless close examination is made of each 

 individual sheep. (See fig. 5.) As the disease advances increasingly 

 large areas become entirely denuded of wool. Scabs fall and are 

 replaced by thicker and more adherent crusts. The skin finally 

 becomes more or less bare, tumefied, is greatly thickened, and may 

 crack and bleed. Unless properly treated many of the animals 

 will die. 



