156 Journal op the Department op Agriculture. 



Ill Older to main tain a constant strength of the dip the use of a dip- 

 tester, a so-railed isometer, is advisable. Instructions for the use of 

 the instrument are sold with it. If the dip is not diluted by rain it 

 generally does not lose much in streng'tli. and the more frequentlj- it 

 is used the less strength it will lose. It is only in dips that are out 

 of use foT a long period that a change of aisenite to arsenate may take 

 place, which then has a bad effect on the skin. Therefore a dip whicli 

 has been out of use foi- some time should be stirred up before cattle 

 are sent in. 



Although dipping can be stated io be generally harmless for 

 cattle, it will be advisable to accustom the cattle to the dip by using 

 first the weaker solution and later on the stronger ones. Such a 

 ])rocedure will prevent cracking of the skin. Oxen appear to be 

 l)articularly affected by the arsenic dip when worked. The effects 

 show themselves usually three to four days after dipping, and the 

 oxen are noted soon to tire when in wagon or plough and to show 

 dyspnoea, in severe cases stretching out the tongue and finally falling 

 down when not outspanned. These symptoms are particularly noted 

 in liot weather. Apoplectic death has also been seen in such cases. 



Dii)ping has a good effect generally on the animals: it improves 

 their condition and gives them a sleek and glossy skin. It has, of 

 course, also an influence on skin diseases generally, and prevetits hair- 

 balls in calves which are the result of licking the tick-infested skin. 

 AVherever it is intended to reduce the ticks to a minimum in the 

 sliortest possible time the dipping of horses running on the veld is 

 also advisable. Horses get accustomed to' dipping just as cattle 

 do. Neither should goats and the smooth-haired Africander 

 and Persian sheep be omitted. Tliese inimals are to a great extent 

 the hosts of the red tick, which, as stated before, it is difficult to 

 reach on cattle. It should therefore be destroyed on all its hosts. 



Animals running on the veld that for some reason or other cannot 

 be dipi)ed — such as cows heavy in calf, etc. — should at least be 

 sponged or dressed at short intervals. The use of fatty substances 

 with an addition of tar or resin is recommended for a dressing. It 

 must, however, be borne in mind that tlie object of dipping is to get 

 rid of ticks from the farm ; cattle and other animals act as collectors, 

 the codlected ticks are then destroyed by means of the dip. Fatty 

 substances will prevent ticks attaching. It would thus appear that 

 the cleaning of ears, sheath, brush, and anus is better carried out 

 with the di})ping liquid itself, care being taken at the same time that 

 the ticks are mechanically removed. 



3. Sfarrin// ilie Ticl-.s. — The third metliod of eradicating ticks is 

 the starving process, and this must undoubtedly lead to success in 

 every case where we are able to keep the place, for a sufficient length 

 of time, free of such animals as act as hosts. AVe note that the blue 

 tick will live about eight months only, therefore keeping a pasture 

 free of animals for this period must starve out the ticks. If it is oui' 

 intention to rid a farm of red, brown, and bont ticks this period must 

 be extended over a year. From observations made in connection with 

 East Coast fever, where the freeing of an area from the disease is due 

 to starving out the ticks, it can be deduced that a safe period is fifteen 

 months, and we can assume that this period will free any farm from 

 tick-life provided no host lias access to it. 



