654 DISEASES OF SWINE 



upon the amount of coal-tar derivatives they contain. Each 

 manufacturer has special arguments to offer why his particular 

 product is a little better than any one's else, but any of these 

 dips, put up by a reliable chemical house, will be found to be 

 effective. 



For dipping purposes, where a large herd is to be handled, it is 

 advisable to have a dipping tank or vat into which the hogs can be 

 driven and forced to wallow through the dipping solution. There 

 should be enough of the solution in the tank to entirely cover the 

 body of the animal, and the tank should be long enough so that it 

 will take the animal several seconds to get through it. In this 

 manner the disinfectant is quickly brought in contact with every 

 part of the skin and the lice are all reached. 



The strength of the solution should be about 2 per cent., that is, 

 to each 25 gallons of water | gallon of the kresol or other dip 

 should be added. If the tank holds 50 gallons of water, add 1 gal- 

 lon of the disinfectant; if 100 gallons of water, 2 gallons of the com- 

 pound, and so on. 



These coal-tar disinfectants will destroy the live parasites, but 

 they will not destroy all of the eggs or nits. In order to accomplish 

 their destruction it is necessary to dip the animals once or twice a 

 week for two or three weeks, in order that the newly hatched Uce 

 be destroyed before they have had time to become mature and lay 

 more eggs. In this manner we can finally rid the animals entirely 

 of the hce, provided they are not running in infested feed lots and 

 sleeping in infested quarters, where they become re-infected with 

 the full-grown lice. 



These coal-tar dips have an added benefit in the treatment of 

 this condition, in that they also reheve the itching and irritation of 

 the skin produced by the bites of the lice and by the secondary urti- 

 caria and eczema. The effectiveness of the dipping process is in- 

 creased if the animals are kept in a fairly close pen for a few hours 

 after dipping, as in this way they rub against each other and brush 

 off large numbers of the lice and nits as well as more evenly dis- 

 tributing the dip. 



Kerosene Emulsion. — Many hog raisers and stockmen have for 

 several years treated hog-hce by use of a kerosene emulsion. This 

 is a milk-like preparation made by combination of ordinary coal 



