486 INFECTIOUS DISEASES DUE TO PROTOZOA 



(a) Hand Picking. — ^When only a few cattle are kept on 

 the farm or in the case of ox teams, removing the ticks by 

 picking, currying or brushing three times a week from 

 May till December effectually protects the pastures from 

 reinfestation with pregnant females and also betters the 

 condition of the cattle themselves. 



(b) Spraying with crude petroleum or some coal-tar dip 

 (5 per cent.) from May till December serves the same 

 purpose in small herds. Sometimes where no spraying 

 mechanism is at hand, the fluids are applied with sponges, 

 brushes or with a syringe. 



(c) Dipping. — Dipping is the most practical method of 

 ridding animals of ticks. It is recommended that all cattle, 

 and also horses and mules if they harbor ticks, be dipped 

 regularly every two weeks during the warm season of the 

 year and until the ticks have disappeared. If dipping were 

 properly carried out and persisted in, a complete eradication 

 of the cattle tick would follow and with it the disappearance 

 of Texas fever. In many tick-infested districts community 

 dipping vats made of wood or concrete are erected to serve 

 a number of farms. The most reliable solution in which to dip 

 ticky animals is arsenic trioxid combined with sodium 

 hydroxid and sodium carbonate. Pine tar may be added to 

 increase the adhesive properties of the bath which gives 

 greater effectiveness against the ticks and reduces the danger 

 of blistering the cattle. For details as to mixing and appli- 

 cation appropriate bulletins should be consulted. 



(d) "Soiling Method." — The ticky cattle are placed in a 

 tick-free pen for three weeks. At the end of this period they 

 are removed to a second tick-free pen and kept in it a further 

 three weeks. If at the end of this time they are found free 

 from ticks they may be placed on a non-infested pasture. If 

 not, they are returned to a pen for two weeks longer. The 

 success of this plan depends upon the fact that all of the ticks 

 drop off the cattle while in the pens and as the animals are 

 removed to a new pen before a new crop of seed ticks can 

 hatch, no opportunity for reinfestation is offered. Obviously 

 the pens must be thoroughly disinfected before using again. 



Freeing Pastures from Ticks. — ^There are several methods 

 of eradicating ticks from infested pastures. 



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