exas rever 



Tick 



By Dr. Mark Francis, 



Professor of Veterinary Science, Texas Agricultural College 



For many years it has been generally 

 known that if cattle raised in what are 

 known as the Northern States be taken 

 south into the South Atlantic and Gulf 

 States, after a few weeks they become 

 sick and die of an obscure disease called 

 "acclimation fever," "bloody murrain," 

 or "Texas fever." 



Not Confined to a Small District— This 



disease is widely distributed, affecting 

 cattle in all parts of the torrid and sub- 

 temperate zones having a low altitude. 

 The disease is due to the invasion and destruction of the red 

 blood corpuscles by a minute animal parasite of the same gen- 

 eral character as the malarial organism of man. It is conveyed 

 from one animal to another by the Cattle Tick only. These two 

 facts are the essential features of this subject, and should be 

 kept in mind. 



How the Disease Is Propagated — The blood of most cattle 

 that have been raised in the Gulf states contains these para- 

 sites, though the animals may appear to be in good health. If 

 the common ticks (Boophilus annulatus) mature on these infected 

 cattle, their progeny will be virulent and be capable of infecting 

 any cattle which are not immune to the disease in question. 

 When the female cattle tick matures, it falls to the ground, and 

 crawls to some dark and suitable place to deposit its eggs. In 

 ten days or so, she will have produced about two thousand eggs. 

 She then dies. Some species of tick produce several crops of 

 eggs, but this one lays eggs but once. 



This simple fact is important, as it greatly simplifies the 

 problem of tick eradication to be mentioned later. The eggs 

 which have been laid will hatch in three or four weeks if the 

 weather conditions be favorable. In winter it may be several 

 months before the eggs hatch. The young ticks have but six 

 legs. We call them larvae. They crawl up on the grass or weeds 

 and simply wait until some animal passes their way, to which 

 they can attach themselves and secure blood which seems neces- 

 sary for their development. If no cattle or other suitable animal 

 happens to give them this opportunity, they perish for lack of 



