502 



DISEASES OF CATTLE. 



ply rapidly and are spread from diseased to healthy cattle by bodily 

 contact, or by pens, stables, railroad cars, etc., recently occupied by 

 mangy cattle. The mites attack the skin and cause it to become 

 thickened and covered with crusts and scabs, with a consequent loss 

 of hair. Intense itching accompanies the disease and affected cattle 

 are more or less constantly rubbing and licking themselves. Pso- 

 roptic mange commences at the root of the tail, or on the neck, or 

 withers, and gradually extends over the back up to the head, over 



the sides, and may 

 finally affect nearly 

 the entire body ex- 

 cept the legs. In 

 serious cases the 

 skin may become 

 ulcerated; the ani- 

 mals become greatly 

 weakened and ema- 

 ciated, and finally 

 die. By taking 

 scrapings from the 

 edges of scabby 

 patches and placing 

 them on a piece of 

 black paper in a 

 warm place the 

 mites may be seen 

 as tiny white objects 

 crawling over the 

 paper, more dis- 

 tinctly if a magnify- 

 ing glass is used. 

 Mange may be con- 

 fused with lousi- 

 ness, ringworm, or 



Pig. 13.— Mite which causes psoroptic scab of sheep— enlarged with any Condition 

 about 100 times. The mite of psoroptic cattle mange is almost . , . . ., 



identical in appearance. ln wll ich tnOTe ls 



itching or loss of 

 hair, but if mites are found there is no question of the diagnosis. 

 The disease is worse during cold, wet weather. Mangy cattle when 

 on good pasture during the summer often seem to recover, but in the 

 fall the disease again appears in a severe form. 



Treatment for psoroptic mange. — The most generally used and most 

 satisfactory method of treating cattle mange consists in dipping the 

 animals in a vat filled with a liquid of such a nature that it will kill the 

 parasites without injuring the cattle. Vats for dipping cattle are built 

 of wood, stone, or concrete, and vary in length from 30 to 100 feet or 



