LICE WHICH AFFECT DOMESTIC ANIMALS 345 



transmission of different diseases of hogs including cholera, although 

 they are now generally believed to be of little importance in this connec- 

 tion. 



Control Measures.- — For the breeder of hogs in considerable numbers 

 there is undoubtedly no better metliod for controlling hog lice than 

 through the use of the dipping vat. A number of insecticides have been 

 found effective against them, including crude petroleum (two inches float- 

 ing on water in the vat), kerosene emulsion, and many of the standard 

 coal tar dips. It is important to get the hogs completely under the dip. 

 In order to insure complete destruction of the species it is necessary to 

 repeat the dipping a second time after a lapse of ten days. 



For the small raisers the expense of installing a vat is unnecessary as 

 the application of any effective material with a spray pump or by hand 

 with a brush is satisfactory. The concrete hog wallow containing water 

 on which is floated a film of crude petroleum is fairly satisfactory, al- 

 though if these wallows are not properly kept they may be objectionable 

 from a sanitary point of view. Others use various types of hog oilers by 

 which the oil is applied to the animals as they rub against the appliance. 

 Still others simply sprinkle the oil on the backs of the hogs from a water- 

 ing pot. Other insecticides are sometimes applied in the same way. 

 Many oils, including kerosene oil, seem to be quite effective. 



The application of insecticides by the use of wallows, hog oilers, sprin- 

 kling cans and similar metliods can not be relied upon to destro^'^ all lice 

 but will give a moderate degree of control if repeatedly attended to. 



To avoid burning the hogs, or other injurious effects, they should 

 be treated towards evening or on cloudy days and should not be over- 

 heated either before or after applications. 



It has been observed that hogs fed on garbage are comparatively 

 or entirely free of lice. This condition is undoubtedly the result of con- 

 tinual application of grease by the wallowing of the hogs in the gar- 

 bage. 



LICE ATTACKING SHEEP 



The lice infesting sheep seldom become so abundant as to be consid- 

 ered of much importance. The so-called foot louse, Linognathus pedalis 

 Osborn, a suctorial species, was found by Osborn at Ames, Iowa, on sheep 

 imported from Canada. It was present onW on a comparatively few of 

 the sheep. Evidently tlie species is not at all common in the United 

 States. It occurs, so far as known, only on the legs, especially in the 

 region of the dew claws and not on tlic heavy wool-parts of the host. This 

 immediatel}^ suggests the use of a shallow wade vat by which a good 

 dclousing agent might be applied without coming in contact with the 

 wool on the body of the host. 



