170 



THE TFLOSPORASIDA AND THE COCCIDLA PROPER 



Immunity : Senger et a I. (1959) found 

 that inocula of 10, 000, 50, 000 or 100, 000 

 oocysts of E. bovis produced a good deal 

 of immunity to reinfection. The immunity 

 developed rapidly, calves being resistant 

 to challenge 14 days after immunization. 

 Immunity persisted to a moderate degree 

 for 2 to 3 months in young calves, and in 

 one group of yearlings there was appar- 

 ently a high degree of immunity 7 months 

 after the last inoculation. An inoculum 

 of 10,000 oocysts did not produce as great 

 an immunity as 50,000 or 100,000 oocysts; 

 there was no significant difference in the 

 degree of immunity produced by the higher 

 doses. All these immunizing doses caused 

 diarrhea and bloody feces; the greater the 

 number of oocysts administered, the more 

 severe and longer-lasting the resultant 

 disease. 



Hammond el al. (1959) found that this 

 immunity was not directed against the 

 schizonts but against the sexual stages or 

 merozoites. They found no significant 

 differences in numbers or size of schi- 

 zonts between immunized and non-immu- 

 nized calves, but the latter had many more 

 sexual stages than the former. 



Remarks : Hassan (1935) described 

 the sporozoites and schizonts of an organ- 

 ism which he named Globidium fiisiformis 

 from 5 zebus with dysentery and rinder- 

 pest in India. The schizonts were found 

 in the abomasum, duodenum and ileum; 

 they often occurred anterior to the ileo- 

 cecal valve, but were not found in the 

 large intestine. They were whitish and 

 measured 0. 4 to 1. by 0. 8 mm. The 

 merozoites were elongate, spindle- 

 shaped, slightly curved-, with one end 

 bluntly rounded and the other finely 

 pointed, 13 by 2 to 2. 5 /i . This form may 

 well be Eimeria bovis. However, the 

 fact that schizonts were found in the abo- 

 masum as well as in the small intestine 

 made Hammond et al. (1946) hesitate to 

 assign it to this species, since they never 

 found schizonts of E. bovis in the abo- 

 masum. 



EIMERLi BRASILIENSIS 

 TORRES AND RAMOS, 1939 



Synonyms : Eimeria boehmi Supperer, 

 1952; Eimeria orlovi Basanov, 1952. 



Hosts : Ox, zebu. In addition, Bohm 

 and Supperer (1956) reported finding this 

 species in several chamois in Austria, 

 but gave no morphological information on 

 which a comparison could be based. 



Location : Unknown. Oocysts found 

 in feces. 



Geographic Distribution : North Amer- 

 ica, South America (Brazil), Europe(Aus- 

 tria), Africa (Nigeria), USSR (Kazakhstan). 



Prevalence : Davis and Bowman (1952) 

 stated that this species is uncommon in 

 Alabama. Hasche and Todd (1959) found 

 it in 6% of 927 cattle in Wisconsin. Torres 

 and Ramos (1939) found it in 3% of 146 

 cattle in Brazil. Supperer (1952) found it 

 in 7% of 130 cattle in Austria. Lee and 

 Armour (1958) saw it frequently in cattle 

 in Nigeria. Basanov (1952) found it in 

 Kazakhstan, USSR. 



Morphology : The oocysts are ellip- 

 soidal, colorless to yellowish or pinkish, 

 smooth, 31 to 49 by 22 to 33 ji, with a 

 mean of 36 to 38 by 26 to 27 j^. The oocyst 

 wall is composed of a single layer. The 

 micropyle is 5 to 6^ in diameter, and is 

 covered by a micropylar cap 8 to 12 [^ wide 

 and 1. 5 to 3 (i high; this cap tends to col- 

 lapse on storage in unprepared feces in 

 the refrigerator. An oocyst polar granule 

 is present. An oocyst residuum is absent. 

 The sporocysts are elongate ovoid (with a 

 fine "operculum", according to Torres and 

 Ramos), 16 to 22 by 7 to 9 1^ (Supperer). 

 A sporocyst residuum is present. 



The sporulation time is 6 to 7 days at 

 27° C (Lee and Armour, 1958) or 12 to 14 

 days at 20° C (Supperer, 1952). 



Life Cycle : Unknown. 



Pathogenesis : Unknown. 



