[PRor. Rot. Soc. Victoria, 25 (N.S.), Ft. I., 1912.] 



Akt. 11. -The Iiitrudactioi) and Spread of the CaNlc Tick 



(Boophilus ainiulatus, var. riiicropiiis), and of 



ilie Associated Disease Tirl- Fever ( B((hesiasis) in 

 Aiisti'(dia. 



By J. A. GILRUTH, D.V.Sc, .M.iJ.C.V.8., F.R.S.E. 



[Rend Hlh March, 1912J. 



Australia, although a large portion of its local area is situated 

 within the tropical belt, is happily free from almost all those i)rotozoan 

 diseases which affect the doiiiesticated animals in tropical regions else- 

 where. For this she has to thank not quite so much the foresight of 

 her administrators, as her insular position, the fact that no domes- 

 ticated animal is indigenous, and above all, the fact that all her 

 importations have been derived almost solely from the original home 

 of her people, namely, Great Britain. 



Nevertheless, there are at least two specific diseases present in Aus- 

 tralia, both affecting cattle, and Ijnth the cause of considerable pecu- 

 niary loss to stockuwners, either directly or indirectly, and these are 

 diseases which are unknown amongst British stock. The diseases in 

 cjuestion are " Tick Fever " or " Redwater " (Babesiasis) and the so- 

 called " Worm Nodules, ' due to the parasite Oncliorcrca (jihxoni, 

 which is dealt with in another paper. 



Tick fever is not found all over Australia. It is rare in the 

 southern Stoies, and has not yet appeared far south of the tropical 

 border. The evidence all points to its greater prevalence the further 

 north stock are pastured. 



Now, as the Australian tick fever is not present amongst the British 

 herds which have formed the basis of our Australian herds, it is highly 

 incumbent on us to ascertain exactly how it came to be introduced, or 

 at least the most probable sources of introduction. But to do so one 

 must first of all consider which countries are most likely to have been 

 in a position to affect Australia in such a manner. 



So far as I can gather there are no official records of stock importa- 

 tions ever having been made through any ports other than the main 

 ports of the southern part of the continent and Queensland. At these 

 ports there. has been almost from the earliest days of settlement a 

 more or less satisfactory system of inspection and quarantine, and the 

 most cursory official examination could have hardly failed to detect the 

 tick parasite, which is a necessary agent in the natural transmission of 



