296 



THE PIROPLASM.\SIDA 



is B. auslralis. Transmission takes 

 place thru the egg. 



Pathogenesis: In Australia, IJ. 

 argenllna is more pathogenic than B. 

 bigeiiihia (Pierce, 1956). Daly and Hall 

 (1955) found that the mortality in Aus- 

 tralian cattle inoculated with B. bigenuna 

 was 30% and that of cattle inoculated with 

 B. argeiiliiia was 70 to 80Vo. The clinical 

 signs, lesions, etc. are similar in both 

 diseases. 



Immunity : Premunition following 

 recovery from B. argeiilina infections 

 lasts less than 2 years, and the minimum 

 time at which cattle regain susceptibility 

 is 5 to 6 months (Pierce, 1956). Cattle 

 infected with B. bigemina are resistant 

 to infection with B. argentina (Legg, 1935; 

 Seddon, 1952), but those infected with B. 

 argentina are susceptible to infection with 

 B. bigemina (Seddon, 1952). 



Diagnosis : Same as for B. bovis. 

 The trophozoites can be found more easily 

 in smears from the heart or kidney than 

 in the peripheral blood. 



Treatment : Same as for B. bovis. 



BABESIA MAJOR 



(SERGE NT, DONATIEN, PARROT, 



LESTOQUARD AND PLANTUREUX, 



1926) 



Synonyms: Babesiella major, Fran- 

 caiella colchica. 



Hosts : Cattle, 



Location : Erythrocytes. 



Geographic Distribution : Europe, 

 USSR. 



Morphology : The trophozoites re- 

 semble those of B. bovis, but are larger. 

 The piriform, paired forms measure 

 2. 6/1 by 1. 5(i , and the round ones are 

 1,8/i in diameter. The parasites lie in 

 the center of the host erythrocyte. 



Life Cycle : Similar to that of B. bovis. 

 The vector in the USSR is Boopliilus cal- 

 caratus . 



Pathogenesis : This species is con- 

 siderably less pathogenic than B. bovis. 

 There is little fever, relatively slight 

 anemia, and experimentally infected ani- 

 mals show no clear clinical signs of illness. 



Immunity : This species can be dif- 

 ferentiated from B. bigemina and B. ber- 

 bera by cross-immunity studies. 



Treatment : Same as for B. bovis. 

 Trypan blue is ineffective against B. 

 major. 



BABESIA MOTASI 

 WENYON, 1926 



Synonyms : Haematococcus ovis pro 

 parte, Piroplasma ovis. 



Hosts : Sheep, goats. 



Location : Erythrocytes. 



Geographic Distribution : Southern 

 Europe, Middle East, USSR, Indochina, 

 Africa, and other parts of the tropics. 



Morphology : This is a large form, 

 measuring 2. 5 to 4 by about 2/1 . The 

 trophozoites resemble those of B. bigem- 

 ina and are usually piriform. They occur 

 singly or in pairs; the angle between mem- 

 bers of a pair is acute. 



Life Cycle : Similar to that of B. 

 bigemina. The vector in Roumania is 

 Rhipicephaliis bursa, that in Sardinia is 

 Haemaphysalis punctata, and those in the 

 USSR are Dermacentor silvarum and 

 Haeniapliysalis otopliila. Transmission 

 occurs both thru the egg and stage-to- 

 stage in R. bursa. 



Pathogenesis : This species may 

 cause either an acute or chronic disease. 

 Fever, prostration, marked anemia and 

 hemoglobinuria are present in the acute 

 disease, and affected animals often die. 

 There may be no characteristic signs in 

 the chronic disease. 



Immunity : Sheep which are immune 

 to B. molasi are not immune to B. ovis 

 and vice versa. 



