THE ANIMAL PAllASITES OF CATTLE. 527 



there is itching or loss of hair, but if niites are found there is no ques- 

 tion 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 fsor optic 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 more. They vary in width from 4 to 7 feet at the top, and 2 to 

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

 row chute through which the cattle are driven leads up 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 give the ani- 

 mals a foothold. A draining pen with floor sloping back toward the 

 vat is generally provided. The dip should be used warm, 100° to 

 110° 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- 

 ping fluid may be heated from a steam boiler by pipes or hose, or 

 water heated in large iron cauldrons or tanks may be used for charg- 

 ing the vat, and hot water with a proper quantity of dip added from 

 time to time as the dipping fluid becomes cool. 



If Beaumont oil emulsion be used, one treatment will be sufficient. 

 "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 ^gg stage or as fecundated females. 



The following dips are approved b}^ the Department of Agriculture 

 for dipping mangy cattle which are to enter interstate commerce : 



LIME-AND-SULPHUB DIP. 



The lime-and-sulphnr dip is made in the proportion of 12 pounds of unslalied 

 lime, 24 pounds of the flowers of sulphur, and 100 gallons of water. 



Directions for prepmHng 100 gallons of dip. — Weigh out the lime, 12 pounds, 

 and sulphur, 24 pounds. Place the unslaked lime in a shallow, water-tight box 

 similar to a mortar box, or some suitable vessel, and add enough water to slake the 

 lime and form a lime paste or lime putty. Sift into this lime paste the flowers 

 of sulphur and stir well ; then place the lime-and-sulphur paste in a kettle, boiler, 

 or tank containing 30 gallons of water, the water being first heated nearly to the 

 boiling point. Boil the mixture for two hours at least, stirring frequently ; add 

 water occasionally to maintain the original quantity. Allow the mixture to 

 settle in the tank or draw the entire contents of the kettle or boiling tank into a 

 large tub or barrel placed near the dipping vat and provided with a buughole 



