LICE WHICH AFFECT DOMESTIC ANIMALS 337 



them too strong or in applying them too vigorously, it has been felt that 

 less dangerous applications can be made with even better results. 



One thing can be said for them, however, and that is regarding their 

 effectiveness. That the lice are killed by the application of arsenical 

 washes there is no doubt. 



One formula recommended is as follows: 



% lb. caustic soda (85% pure). 



% lb. white arsenic (99% pure) fine powder. 



% lb. sal soda. 



y^ pt. pine tar. 



30 gallons water. 



In preparing and using any arsenical dip or wash one should re- 

 member that arsenic is a poison and take precaution to avoid injury. 

 If animals are allowed to drain where they may drink the solution, or 

 feed when the solution is dripping off of them, they are liable to be 

 poisoned. 



Care should be taken too that the hands should not be exposed any 

 more than necessary. 



The arsenical washes may be necessary to use for dips for large 

 herds and under range conditions, where tick infestations also occur, but 

 their us;e is questioned for smaller tick-free herds. 



For fuller information regarding arsenical dips and washes for cattle 

 on range see Farmers' Bulletins Nos. 608 and 909. 



Nicotin washes. — These are questionable owing to the fact that ex- 

 treme care must be taken in order to keep the wash away from the cows 

 so that they will not get some of it internally. Cows are particularly 

 susceptible to poisoning from tobacco decoctions. 



MISCELLANEOUS KEMEDIES 



Greases. — ^Mercurial ointment is one of the' most effective of lice 

 killers though it is very liable to cause burns even when it is diluted con- 

 siderably. This ointment diluted with twelve parts of vaseline was used 

 on some cows and burns resulted from the application. 



KeroseTie Oil and Lard have been used considerably for cattle lice 

 but the danger of injury to the skin with the use of kerosene oil, unless 

 very thoroughly mixed with some diluent, is always present. 



With the majority of the greases, the inability to spread properly 

 makes their application expensive because of the quantities of material 

 required to cover the regions infested by lice. 



Powders. — ^Dusting powders are usually sulphur, naphthalene, and 



