CHAPTER VI. 



DISEASES CAUSED BY PROTOZOA. 



TEXAS OR SOUTHERN CATTLE FEVER. 



Synonyms. "Red water' ' ; Mexican fever ; Spanish fever ; 

 Splenic fever, " Bloody Murrain". 



§ 179. Characterization. Texas fever is an infectious 

 blood disease of cattle, characterized by rise of temperature, 

 hemoglobinuria, destruction of the red blood corpuscles and 

 the presence in the blood of a protozoan parasite which is trans- 

 mitted from animal to animal by means of the cattle tick. 



It is believed to be identical with the hemoglobinuria in 

 Roumania, Tick fever in Australia, and "La Tristeza " in 

 South America. It has been named malaria des bovides by 

 Celli and Sentori and Malaria Bovine by Lignieres. Although 

 it differs in many ways from human malaria, the analogy is so 

 close respecting the specific cause, wide distribution and 

 means of transmission that bovine malaria seems to be a very 

 suitable name for this affection. At least it has the advantage 

 of not stigmatizing any locality. 



The peculiar and interesting feature of this affection is the 

 fact that cattle raised in the infested districts become im- 

 munized so that they do not suffer from the disease but the}- 

 carry its specific organism in their blood. When imported 

 into non-infested districts, they transmit the virus, by means 

 of the cattle tick, to susceptible animals, but remain them- 

 selves perfectly well. 



§ 180. History. There is little knowledge concerning 

 the early history of this disease. With the development of 

 commerce, however, the shipping and interchange of animals 

 gradually came into prominence and with it all, this disease 



