THE TELOSPORASIDA AND THE COCCIDIA PROPER 



175 



When mature they measure about 10 by 

 13(1 and contain 24 to 36 merozoites. 

 They lie distal to the host cell nucleus. 

 Merozoites are first seen 7 days after in- 

 fection. They are about 5 by 12jll, have 

 their nucleus near the tapering end and 

 contain 2 refractile globules. Davis and 

 Bowman did not determine the number of 

 asexual generations, but believed that 

 there is more than one. The mature schi- 

 zonts late in the cycle are slightly larger 

 than the early ones. 



Macrogametes are first seen 12 days 

 after infection. They occur in the epithel- 

 ial cells of the glands and to a lesser ex- 

 tent of the surface of the lower small in- 

 testine, cecum, colon and rectum, and 

 rarely in the upper small intestine. They 

 are about 11 by 14ji and contain 1 or 2 

 rows of plastic granules. Microgameto- 

 cytes are first seen 15 days after infection 

 in the same location as the macrogametes. 

 They measure about 10 by I4.fi when ma- 

 ture. Immature oocysts are first seen 12 

 days after infection. 



Pathogenesis : E. ziirnii is the most 

 pathogenic coccidium of cattle. In acute 

 infections it causes a bloody diarrhea of 

 calves. At first the feces are streaked 

 with blood. The diarrhea becomes more 

 severe, bloody fluid, clots of blood and 

 liquid feces are passed, and straining and 

 coughing may cause this mixture to spurt 

 out as much as 6 to 8 feet. The animal's 

 rear quarters may look as tho they had 

 been smeared with red paint. Anemia, 

 weakness and emaciation accompany the 

 dysentery, and secondary infections, es- 

 pecially pneumonia, are common. This 

 acute phase may continue for 3 or 4 days. 

 If the calf does not die in 7 to 10 days, it 

 will probably recover. 



E. zurnii may also be associated with 

 a more chronic type of disease. Diarrhea 

 is present, but there may be little or no 

 blood in the feces. The animals are em- 

 aciated, dehydrated, weak and listless, 

 with rough hair coats, drooping ears and 

 sunken eyes. 



The lesions of coccidiosis have been 

 described by Boughton (1945) and Davis 



and Bowman (1952) among others. A gen- 

 eralized catarrhal enteritis involving both 

 the small and large intestines is present. 

 The lower small intestine, cecum and colon 

 may be filled with semi-fluid, bloody ma- 

 terial. Large or smaller areas of the in- 

 testinal mucosa may be eroded and des- 

 troyed, and the mucous membrane may be 

 thickened, with irregular whitish ridges in 

 the large intestine or smooth, dull grey 

 areas in the small intestine or cecum. 

 Diffuse hemorrhages are present in the 

 intestines in acute cases, and petechia;l 

 hemorrhages in mild ones. 



EIMERIA BOMBA YANSIS 

 RAO AND HIREGAUDAR, 1954 



Host: Zebu. 



Location : Unknown. Oocysts found 

 in feces. 



Geographic Distribution : India. 



Prevalence : Unknown. Rao and 

 Hiregaudar (1954) stated that its preva- 

 lence was great in calves in a dairy herd 

 near Bombay. 



Morphology : The oocysts measure 

 32 to 40 by 20 to 25 |i with a mean of 37 by 

 22.4jLL. They are ellipsoidal, tending to- 

 ward the cylindrical, some with parallel 

 sides and others with 1 side straight and 

 the other slightly convex. The micropyle 

 is 2 to 4 ji in diameter, with a thickened 

 wall around it. The oocyst wall is smooth, 

 transparent, homogeneous, pale yellowish 

 brown, 1 to 1.5/i thick. The sporocysts 

 are 12 to 15(j, long, oval, with 1 end a 

 little more pointed than the other. An 

 oocyst residuum is absent, but a sporocyst 

 residuum is present. The sporozoites are 

 4 to 6 |i long. The sporulation time is 2 

 to 3 days. 



Pathogenesis : Unknown. 



EIMERIA MUNDARAGI 

 fflREGAUDAR, 1956 



Host: Zebu. 



