PIROPLASMOSES 491 



Evertsi, sinus, nidens and capensis) are responsible for its 

 spread. The parasite does not pass through the egg as in the 

 case of Texas fever, and the disease cannot be transmitted 

 from immune animals to healthy cattle. The infection takes 

 place only among young cattle when on pasture. Adult 

 animals are immune. As noted, the disease cannot be trans- 

 mitted by the blood, although transmission has been accom- 

 plished to susceptible animals by introducing intra-abdomi- 

 nally large pieces of spleen. 



S3rmptoms. — ^The period of incubation is ten to twelve 

 days. The first symptoms are those of high fever, salivation, 

 bloody diarrhea, swelling of the lymph glands of the throat, 

 emaciation and weakness. Anemia and hemoglobinuria are 

 usually not present. The appetite of the patient may be 

 retained until the last stages. 



Prognosis. — ^The disease is very malignant, the mortality 

 among young cattle reaching 60 to 90 per cent. 



Prophylaxis. — Is similar to that of Texas fever and depends 

 upon the eradication of the tick. The value of blood and 

 serum inoculations is very questionable. 



Piroplasmosis of the Horse {Biliary Fever). — ^Definition. — 

 The piroplasmosis of horses is an infectious, blood disease 

 which occurs chiefly in Italy, Russia and also In Africa and 

 India. It is due to the Piroplasma equi. 



Occurrence. — ^The disease occurs so far as reported only 

 in the countries noted above. In Russia it is most common 

 among young, native horses which run on low, swampy 

 pastures. Aged horses imported from non-infected localities 

 are, however, susceptible. 



Etiology. — ^The disease is due to a Piroplasma equi, a small, 

 polymorphous parasite found in the red blood corpuscles. 

 The carriers of the infection are several varieties of ticks. 

 In Russia the Dermacentor reticulatus and in Africa the 

 Rhipicephalus Evertsi are the carriers. Besides horses, 

 asses, and mules, zebras and quaggas take the disease. The 

 disease may be transmitted by blood from immune horses. 

 While one attack produces immunity this immunity is readily 

 overcome by anything which decreases the resistance of the 

 animal (hard work, other diseases). Imported horses are 

 much more susceptible than natives. 



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