526 



DISEASES OF CATTLE. 



are to be treated the dip may be applied with a brush or cloth, or with 

 a small spray pump, or a mixture of kerosene one-half pint and lard 

 1 pound may be smeared on the body. 



MANGE, ITCH, SCAB.^ 



Cattle are subject to four kinds of mange, of which common mange 

 or psoroptic mange is the most important. 



Psoropt'w viange of cattle is caused by a species of small mites 

 (fig. IG) which multiply 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 be- 

 come thickened and 

 covered with crusts 

 and scabs, with a 

 consequent loss of 

 hair. Intense itch- 

 ing accompanies the 

 disease and affected 

 cattle are more or 

 less constantly rub- 

 bing and licking 

 themselves. P s o - 

 roptic mange com- 

 mences at the root 

 of the tail, or on the 

 neck, or withers, 

 and gradually ex- 

 extends over the 



Fig. 1G.— Mite wnich causes psoroptic scab of slieep— back Up to the head, 

 enlarged about 100 times. The mite of psoroptic cattle over the sides and 

 mange is almost idr-ntical in appearance. r» n ^ tv 



may nnally anect 

 nearly the entire body except the legs. In serious cases the slcin 

 may become ulcerated ; the animals become greatly weakened and 

 emaciated, and finally die. By taking scrapings from the edges of 

 scabby patches and placing them on a piece of black paper in a wann 

 place the mites may be seen as tiny white objects crawling over the 

 paper, more distinctly if a magnifying glass is used. Mange may be 

 confused with lousiness, ringworm, or with any condition in which 



1 For a fuller discussion see Farmers' Bulletin IJ 

 partment of Agriculture. 



issued by the United States De- 



