LICE WHICH AFFECT DOMESTIC ANIMALS 347 



comes a pest of importance in goat flocks. The lice are especially in- 

 jurious to the kids, and their attack together with that of the biting lice 

 is thought to cause material reduction in the number of kids raised to 

 maturity. On the kids the lice are present on all parts of the body but on 

 the mature goats they are usually more numerous where the hair is not 

 very thick. 



Control. — In proceeding against goat lice it is important to deter- 

 mine whether biting or sucking lice are giving trouble. In many flocks the 

 former are practically the only kind present and in such cases it is more 

 economical to treat the flock with sodium fluoride in the dust form than 

 to dip it. This is especially true when dipping vats are not at hand. 

 We have found that a high degree of effectiveness (90 to 100 per cent 

 destruction) may be obtained by applying the sodium fluoride with a 

 dust gun to the flock in a pen or as the goats are driven through a 

 chute. It does not seem to be necessary to drive the dust into the mohair 

 especially and only a small amount — about one-third of an ounce per 

 head — is necessary. 



In the experiments carried out by Mr. D. C. Parman at Uvalde, 

 Texas, nicotine sulphate used at a strength of 0.07 per cent nicotine was 

 found to give complete control of sucking lice but was less effective 

 against the biting species. On the other hand the standard arsenical 

 dip (white arsenic 8 pounds, sal soda 24 pounds, pine tar one gallon, and 

 water 500 gallons) gave complete destruction of both forms of lice with 

 one dipping. As the arsenical dip is probably the cheapest material ob- 

 tainable it should be recommended above all others where both biting and 

 sucking lice occur in a flock. Goats are usually bunched and sheared in 

 the spring and fall, and following shearing is a good time to treat the 

 entire flock for lice. 



LICE OF THE HORSE 



Horses are quite commonly infested with one biting and one sucking 

 species, Hcematopmus asini Linnaeus and Trichodectes parimipilosus 

 Piaget. It is the writer's impression that the biting louse predominates 

 throughout this country, however, it is not an infrequent occurrence to 

 find herds heavily infested with the sucking louse. It is probable that a 

 careful study of the lice of horses will show that in certain regions one 

 predominates, while in others the other form may be more abundant. 



While it is probable that both forms can breed on asses and mules it is 

 certainly true that these animals are much less subject to louse attacks 

 than the horse. 



Horses which are worked more or less regularly and properly groomed 

 are usually troubled very little from lice, but colts and animals on the 



