54 CIRCULAR 148, U. S. DEPARTMENT OF AGRICULTURE 



In dipping for lice it is not necessary to hold horses in the vat, but 

 if they have scabies they should be held in the vat 2 or 3 minutes. 

 After leaving the vat the animals should be held in the draining pens 

 until all surplus dip has drained off their bodies. Dipping should be 

 finished for the day early enough to dry the animals before sunset. 



Before approving a dip for use in official dipping one of the require- 

 ments of the Bureau of Animal Industry is that there shall be a 

 practical field test for such dip. Of the various classes of dips used 

 on horses, three only are on the approved list — arsenicals, lime- 

 sulfur, and nicotine. Of these the two most commonly used are the 

 lime-sulfur dip for mange and the arsenical dip for lice and ticks. 



ARSENICAL DIP 



Arsenical dip, when properly used, eradicates biting and sucking 

 lice, but it is not an effective remedy for mange. Prepared arsenical 

 dips have been placed on the market, but those which are permitted 

 by the Government for use in dipping cattle for southern fever ticks 

 are suitable for use in dipping horses, mules, and asses for lice. The 

 instructions on the label of the container should be followed in diluting 

 and using ready-prepared dips. The arsenical dip is not usually 

 warmed or heated in the vat. 



It should be remembered that arsenical dip is a poison, and precau- 

 tion should be taken to prevent injury to man or animal. When it is 

 handled and used with proper care it is a safe and effective remedy. 

 Care should be taken not to get the clothing wet with the dip, and the 

 hands should be washed frequently to prevent possible absorption of 

 arsenic. 



Freshly treated animals should be held in the draining pens or 

 other suitable place until all surplus dip has drained off. If allowed 

 to drain where pools of dip collect from which the animals may drink, 

 or if the pasture or feed becomes soiled with arsenical dip, losses are 

 liable to occur. 



If home-made arsenical dip is preferred to the proprietary brands, 

 see United States Department of Agriculture Farmers' Bulletin 1057 

 for full instructions for making it. 



LIME-SULFUR DIP 



Proprietary brands of liquid lime-sulfur may be purchased, and 

 many of them are equal to or even better than the home-made product. 

 Manufacturers have also placed on the market a product commonly 

 known as dry lime-sulfur, made by evaporating, in vacuo or in the 

 presence of an inert gas, concentrated lime-sulfur solution to which 

 a small amount of cane sugar has been added to act as a stabilizing 

 agent. Dry lime-sulfur is readily soluble in hot water, and it is 

 being extensively used as a dip for animals and as an insecticide for 

 plants. Prepared dips should be diluted and used in accordance with 

 instructions printed on the label of the container. Lime-sulfur dips 

 are efficacious and dependable remedies for mange, but they are not 

 effective against lice and ticks. 



Home-made lime-sulfur dip is made in the proportion of 12 pounds 

 of unslaked lime (or 16 pounds of commercial hydrated lime) and 24 



