by t. harvey johnston and m. j. bancroft. 22t 

 Habituation of Cattle to Tick Infestation. 



Hunt says (1899, p. 118) that two things only appear 

 to be effective against tick poverty — ^habituation and dip- 

 ping. " By use and wont, cattle become to a great extent 

 tick proof and by dipping they may be relieved from time 

 to time till this tick proof condition is established. 

 The comparative immunity to tick irritation wliich comes 

 of habituation, does not necessarily afford any protection 

 against Texas fever." The same idea had already been 

 expressed by him in 1898 (1898, p. 450). Pound (1899, p. 

 117) stated that some immunised cattle in grossty-infested 

 districts were in no way inconvenienced by tick infestation 

 while others became gradually inured to the irritation 

 and annoyance caused by the ticks, more particularly in 

 their larval stages. Though dips are of unquestionable 

 value in combating the poverty from gross infestation, 

 they are quite ineffective in protecting cattle from the 

 fever (Hunt, 1898, p. 450). 



" It is said that in time the cattle become habituated 

 to ticks and do not suffer from the effect first described 

 (tick worry and tick sores). I understand that their 

 acquisition of this satisfactory state implies fatness or at 

 least good condition. It is so far in keeping with this 

 statement that the few animals in our herd which remained 

 fairly fat suffered least. But I could not decide, 

 whether the animals did not suffer because they remained 

 fat, or remained fat because they did not suffer. They 

 appeared to harbour few ticks, and it is at least a plausible 

 supposition that the maintenance of a healthy skin, with 

 plenty of fat under it, and normal secretion of fatty 

 sebaceous matter upon it, affords an undesirable and less 

 tenable resting place for ticks than when the functions of 

 the skin are less perfectly discharged oAving to leanness 

 and ill health." (Tidswei!, 1900, p. 12). 



Stewart (1906, p. 1156) has mentioned that cattle 

 newly exposed to infestation not only suffer more from tick 

 irritation than those accustomed to ticky pastures, but 

 become more grossly infested, while those born and reared 

 on infested pastures seem to acquire a certain tolerance to 

 the tick. 



