518 



DISEASES OF CATTLE. 



IIS blue lice, and one biting louse {Trichodectes scalaris), commonly 



known as the red louse. 



The blue lice (figs. 12 and 13) suck the blood of cattle and are more 



injurious than the red lice (fig. 14). Unless very abundant the latter 

 cause little injury. If numerous they irritate 

 and worry their host probably more by their 

 sharp claws than by their bites, as their food 

 seems to consist entirely of particles of hair and 

 dead skin. 



Cattle lice rcj^roduce by means of eggs or nits 

 (fig. 15) Avhicli they fasten to the hair. The blue 

 lice infest chiefl}' the neck and shoulders; red lice, 

 ■when present, may be found almost anywhere on 

 the bod}', but are usually most numerous on neck, 

 shoulders, and at the roct of the tail. 



On account of the itching caused by the lice, 

 infested cattle rub against posts, trees, etc., and 

 lick themselves, the hair sometimes coming out 

 and the skin becoming thickened so that mange 

 may be suspected. 



Treatment for lice. — Cattle infested with lice 



should be dipped in the spring and again in the fall, using a cresol or 



nicotin dip (see p. 521), or Beaumont oil emidsion (see p. 522). The 



ar.senical dip (see p. 173) is also another remedy which may be etfect- 



\\it\y used against lice. ^Alien possible a 



second dipping should be given after the 



lapse of 10 to 14 days, and in some cases 



several treatments may be necessary before 



the lice are brought under control. The 



dips mentioned are, as a rule, more effica- 

 cious against lice than lime-sulphur dip. 



Though lime-sulphur is an excellent mange 



remedy, it is less satisfactory for lice, espe- 



jially blue lice. If only a few cattle are to 



be treated the dip may be a])p]ied with a 



lu'ush or cloth, or with a small spray pump, 



fir a mixture of kerosene one-half pint and 



lard 1 pound may be smeared on the bodv. 



Fin. 12. — Sliort-nosod 

 blue louse {TSwina- 

 topinus euryslenius) 

 of cattle. Enlarged. 

 (From Bureau of 

 Fntomolog:y. ) 



Fig. !.■!. — Long - nosed blue 

 louse [Liiioipiathiis viluli) 

 of cattle. Enlarged. (From 

 Ilureau of Entomolos.v.) 



MANGE, ITCH, SCAB.' 



Cattle are subject to four lands of mange, of wliich common mange 

 or psoroptic mange is the most important. 



' For a fuller discussion see Farmers' Bulletin 152, issued by the United States De- 

 partment of Agriculture. 



