352 VETERINARY HYGIENE 



the most favourable conditions the life-cycle from egg to egg would 

 be about 24 days. 



The Hsematopine louse is far more common on the horse than 

 is the Trichodect, thus Hall found 22 cases were H. assini and 

 but 2 Trichodectes out of 24. 



PREVENTIVE MEASURES. Maintaining the body in a clean con- 

 dition, by grooming in the case of horses, washing and grooming 

 for dogs, grooming for cows and dipping for sheep, is the chief 

 deterrent to the spread of lice. Clean bedding and a sufficiency 

 of good, nourishing food are also important factors. 



Horses brought up from grass are frequently found infested 

 with lice. 



If lice appear on a horse in a stud it is wise to treat the entire 

 stud with suspicion as the vermin are readily carried on grooming 

 tools. Clipping and singeing are the initial steps to take toward 

 the eradication of these disgusting pests, and a suitable parasiticide 

 dressing should follow. Whatever dressing, dip, or wash is used 

 it is important to remember that many eggs escape destruction and 

 therefore the treatment should be repeated weekly for 3 or 4 weeks. 



For cattle or sheep any approved sheep dip is suitable, the 

 former may be washed the latter dipped. The application of sheep 

 dips to the bodies of horses is to be done with great caution, 

 especially if they contain arsenic. Pigs may be dressed with any 

 non-blistering oily dressing and cottagers frequently rub lice- 

 infested pigs with lard. 



Various dressings are advocated for the destruction of lice and 

 their eggs. The following is recommended for cattle : Arsenious 

 acid, 1 oz. ; soft soap, 2 ozs. ; carbonate of soda, 1 ozs. ; water, 2 

 pints. Boil the whole together and dilute to 5 gallons. 



Mayr* recommends the use of Ikaphthisol, a white powder con- 

 sisting of magnesium carbonate, bolus alba, talc, crude cresol, sapo 

 medicatus, and oxytoluol or cresyl alcohol. From 5 to 7 ounces of 

 this powder is to be dusted on to a horse ; this is said to kill the lice 

 in a few minutes. Mangin's method of destroying lice and 

 eggs is as followsf : Eau de Javel, 400 c.c. ; potash soft 

 soap, 200 grammes; water, 10 litres. This quantity is suffi- 

 cient for one horse. The soap is dissolved in hot water and the 

 Eau de Javel (hypochlorite of sodium) is added immediatelv 

 before washing begins. Mangin claims that eggs as well as lice 

 are destroyed. The solution should be left to dry on the animal. 



*Berliner tierarztl. Wochenscher, XXXII., p. 279, through Vet. Rev., 

 1917, I., p. 85. 



t Rec. Med. Vet., XCIL, through Vet. Rev., 1917, I., p. 396. 



