488 INFECTIOUS DISEASES DUE TO PROTOZOA 



injection the animal develops symptoms of anemia, hemo- 

 globinuria and sometimes bloody diarrhea. Microscopically 

 the blood will show a great diminution of red blood corpuscles 

 and will contain a few piroplasms. In eight to ten days these 

 symptoms temporarily disappear but a month later usually 

 a second reaction sets in which lasts only eight to ten days 

 but is milder in type, the red blood corpuscles showing only 

 a few piroplasms of atypical form. If cattle so treated are 

 two months later turned into infested pastures, a large pro- 

 portion of them will resist natural infection. Some of them, 

 however, will show symptoms of fever which is usually 

 followed by recovery. The losses from this method of 

 immunization are about 10 per cent. Some animals of low 

 resistance die during the process of immunization. This 

 method seems more controllable than the former one and is 

 now much employed to prevent losses among imported 

 susceptible cattle. 



Quarantine Line. — ^The United States Government has 

 established a quarantine line which extends from the sea coast 

 east of Norfolk, Virginia, across the country to the coast of 

 California near San Francisco. This line is a very irregular 

 one and is varied from time to time as counties just south of 

 it are freed from ticks. Roughly, at present, the line extends 

 through the center of Virginia, westward along the north 

 boundary of North Carolina, through the State of Tennessee, 

 along the north boundary of Arkansas to the center of the 

 north boundary of Oklahoma, where it drops suddenly 

 taking a southwesterly course until it reaches the Mexican 

 line along the north border of which it proceeds westward 

 until it reaches the east boundary of California which it 

 follows north as far as the latitude of San Francisco where 

 it again turns westward to the coast. 



Firoplasmosis of European Cattle {Infectious Hemoglobin- 

 uria of the Ox. "Red Water" ^). — Definition. — Firoplasmosis of 

 Em-opean cattle is an infectious blood disease very similar 



• The "red water" of British Columbia and of the Northwestern United 

 States, according to Hadwin, is not due to protozoa, but to poisoning with 

 oxalic acid from the wet, undrained and infertile pastures. The disorder, 

 which is very fatal, usually occurs only among adult cattle. 



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