PREVENTION, SYMPTOMS AND TREATMENT lx y 



and where they will not come in. contact with tkky animals. Then 

 the original tick-infested pasture is not to be restocked until April, 

 when it will be tick-free. This happens because ticks will all have 

 hatched before this, date, and unless they can fasten on an animal 

 they will die. 



2. Cultivating land for a year, without permitting any ticky 

 animal thereon, will rid it of ticks-. 



3. Burning over ticky pastures in spring and fall and keeping 

 off tick animals from, the land will free pastures of ticks. 



4. Feed Lot Method. Fence off three enclosures within a 

 field of maise, millet or other forage. It is well to turn up a 

 furrow against the bottom board of both sides of a fence to keep 

 ticks from escaping. Then ticky cattle on June first are put in 

 these inclosures in rotation, staying in each twenty days. All the 

 ticks will have then fallen off, and the cattle do not stay in any one 

 inclosure long enough to be reinfested by young or seed ticks. 

 The inclosures are then plowed and their edges sprayed with 

 petroleum. The cattle in going from one lot to another should pass 

 on cultivated soil and they must not be fed hay from tick-infested 

 pastures. Neither must water come from such a pasture. 



Immunization of Susceptible Cattle. — If stock is to be sent into 

 a tick-infested region, young animals, six to fifteen months old, may 

 be immunized by either placing a few (25 to 50) virulent young 

 ticks upon them or by injecting 1 to 3 c.c. of defibrinated blood 

 from an immune animal into the one to be immunized. The im- 

 mune animal is one in good health but infested with fever ticks, or 

 one which was so infected the previous year. The injection is made 

 subcutaneously into the disinfected skin of the shoulder — 1 c.c. for 

 an old animal; 2 c.c. for a two-year-old; and 3 c.c. for animals nine 

 to fifteen months old. An attack of Texas fever is produced in 

 which the mortality is 3: per cent., but 7 per cent, more are not 

 rendered immune. If the fever is slight after the first injection, 

 another is made in forty days, increasing the dose 50 per cent. 



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