520 



DISEASES OF CATTLE. 



give the animals a foothold. A draining pen with floor sloping back 

 toward the vat is generally provided. The dip should be used warm, 

 100° to 10.")° F., and the cattle should be held in the vat for two 

 minutes to insure thorough action of the dip. The head of each 

 animal should be ducked at least once. Care should be taken that 

 the vat contains a sufficient depth of fluid to swim the animals to 



be dipped. The dip- 

 l^ing fluid may be 

 heated from a steam 

 boiler bj' pipes or 

 hose, or water heated 

 in large iron caul- 

 drons or tanks may 

 be used for charging 

 the vat, and hot 

 water with a proper 

 quantity of dip 

 added from time to 

 time as the dipping 

 fluid becomes cool. 

 The vat for use in 

 tick eradication (de- 

 scribed in Bureau of 

 Animal Indvistry 

 Circular 207) if sup- 

 plied with heating 

 facilities may be used 

 in treating cattle for 

 mange, but should 

 be of gTeat€r length 

 if many cattle are to 

 be treated. 



If Beaumont oil 

 emulsion is used, ohe 

 treatment will be sufficient and the dip may be used cold. Beaumont 

 oil and similar ci'iule petroleums, however, are difficult to obtain and 

 are rarely used. With other dips two treatments are required, the 

 second treatment being given 10 days after the first. The second 

 treatment is necessary to kill the few parasites which sometimes escape 

 at the first treatment, either in the egg stage or as fecundated females. 



Fic 16. — Mite which causes psoroptjc scab of sheep — 

 enlarged about 100 times. The mite of psoroptic cattle 

 mange is almost identical in appearance. 



LIME-SULPHUR DIP. 



The lime-sulphur dip is made in the proportion of 1"2 pounds of 

 unslaked lime (or 16 pounds o«f commercial hydrated lime — not air- 



