514 



PISKASES OF CATTI.E. 



and affected cattle are more or less constantly rubbing and licking 

 themselves. Psoroptic 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 

 except the legs. In serious cases the skin may become ulcerated; 

 the annuals are greatly weakened and emaciated, and finally die. By 

 taking scrapings from the edges of scabby patches and placing them 

 on a piece of black ])aper in a warm f)lace the mites may be seen Jis 



tiny wliite objects 

 crawling over the pa- 

 per, more distinctly 

 if a magnifying glass 

 is used. Mange may 

 be confused with 

 h)usiness, ringworm, 

 or with any condition 

 in wliich there is itch- 

 ing or loss of hair, 

 but if mites aref ound 

 there is no quest i(tn 

 of the tliagnosis. The 

 disease is worse dur- 

 ing cold, wet weather. 

 Mangy cattle when 

 on good pasture dur- 

 ing the summer often 

 soein to recover, but 

 in the fall the disea^c 

 again appears in a 

 seA'ere form. 



Tr e a t m ent. — The 

 most generally used 

 and most sa tisf actory 

 method of treating 

 rattle mange consists 

 in dipping the ani- 

 mals in a vat filled with a liciuid of such nature that it will kill the par- 

 asites 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 

 more. They vary in width from 3 to 7 feet at the top and 1^ to 3 

 feet at the bottom, and the depth may be from 7 to 10 feet. A nar- 

 row chute through Avhich the cattle are driven leads to one end of the 

 vat, where a steep slide pitches the cattle into the dipping fluid, 

 through which they swim, and climb out of the vat at the 

 other end, which is built sloping and provided with cross cleats to 



KiG. 11.— Mite which causes i)soroi)tic scab of sheep. Enlarged about 

 100 times. The mite of p.soroptie cattle mange i.s almost identical in 

 appearance. 



