80 PARASITES OF THE DOINIESTIC ANIMALS 



into a broad concavity in the thorax. The thorax is broad and appar- 

 ently fused with the abdomen, the two forming a somewhat heart- 

 shaped body with base anterior. The first pair of legs is much more 

 slender than the second and third which are stout and terminated by 

 powerful claws fitted for clasping the hairs. The female measures about 

 1.5 mm.; the male about 1 mm. in length. It infests the hairs of the 

 pubic region and of the armpits, rarely passing to other parts. 



Of these three species Pediculus humanus is the most widely dis- 

 tributed. 



Pediculosis, Control and Treatment 



Contagion in pediculosis is due to the rapid succession of generations 

 of lice, their passage from host to host being facilitated by close associa- 

 tion, grooming utensils, blankets, harness, bedding, etc. It is possible 

 for domestic animals of different species to infect each other. Such 

 migrations, however, are usually of an accidental nature, and the 

 parasites will not as a rule remain to multiply upon a host foreign to 

 them. 



Long hair, especially if combined with unclean conditions, predis- 

 poses to lousiness. If in addition there is debihty, the etiologic factors 

 become ideal. Plenty of nutritive food and a thorough cleaning up of 

 animals and their surroundings are, therefore, essential to success, what- 

 ever measures of eradication may be applied. 



After the removal and burning of litter the stables, kennels, etc., may 

 be treated with boiling water and afterward whitewashed or washed with 

 a three to five per cent, creolin solution. For spraying interiors an 

 emulsion of kerosene (formulae, page 48), or the lime-sulphur prepara- 

 tion (page 125) may be used. 



Clipping of long-haired animals, which may include the horse and 

 ox, greatly simplifies their treatment. The Melophagus infesting sheep 

 is removed with the fleece at time of shearing, the animal soon ridding 

 itself of any which may have remained upon the skin. 



Among the considerable number of insecticide agents used upon the 

 bodies of infested animals but one or two of those most effectual and 

 most commonly employed need be mentioned here. A decoction of 

 tobacco, one ounce to the quart of water, as a local application answers 

 well for all animals. In using this preparation the possibility of nicotine 

 poisoning should be kept in mind. Large areas of the body should not 

 be dressed at the same time. 



Horses may be treated with creolin two to three per cent., or kerosene 

 emulsion. Brushes and combs, after having been disinfected by scald- 

 ing, may have a little kerosene sprinkled upon them as they are used. 

 Preparations of kerosene should not be applied to sweating animals or 

 while they are exposed to hot sunshine. Friction with fatty substances, 



