THE TELOSPORASIDA AND THE COCCIDIA PROPER 



22S 



produced by E. meleagridis , E. dispersa 

 and E. gallopavonis , but it is still con- 

 siderable. 



EIMERIA DISPERSA 

 TYZZER, 1929 



Hosts : Turkey, bobwhite quail, ring- 

 necked pheasant, ruffed grouse (?), sharp- 

 tailed grouse (?). 



This species was first described by 

 Tyzzer (1929) from the bobwhite quail. 

 He also found it in the ring-necked pheas- 

 ant. Hawkins (1952) first found it in the 

 turkey. Boughton (1937) reported it from 

 the ruffed grouse (Eonasa umbellus ) and 

 sharp-tailed grouse (Pedioecetes pha- 

 sianelhis campestris). Tyzzer (1929) 

 transmitted it from the bobwhite to the 

 turkey, chicken (producing a light infec- 

 tion) and possibly to the pheasant. Venard 

 (1933) and Patterson (1933) were unable 

 to infect chickens with strains from the 

 bobwhite. Tyzzer (1929) transmitted it 

 from the pheasant to the bobwhite. Haw- 

 kins (1952) infected the bobwhite and 

 Hungarian partridge [Perdix perdix) with 

 E. dispersa from the turkey, but was un- 

 able to infect the pheasant or chicken. 

 Moore and Brown (1952) infected the bob- 

 white with a turkey strain, but, according 

 to Moore (1954), were unable to infect the 

 pheasant. 



Location : Primarily duodenum, but 

 also small intestine. 



Geographic Distribution : 

 America. 



North 



Prevalence : Presumably relatively 

 uncommon. 



Morphology : The morphology of this 

 species was studied especially by Tyzzer 

 (1929) and Hawkins (1952). The oocysts 

 are broadly ovoid, smooth, 22 to 31 by 18 

 to 24 /J, with a mean of 26 by 21 /i . The 

 oocyst wall is composed of a single layer 

 and lacks a micropyle. An oocyst polar 

 granule and oocyst residuum are absent. 

 The sporocysts are ovoid, with a Stieda 

 body. The sporulation time is 2 days. 



Life Cycle : Tyzzer (1929) and Haw- 

 kins (1952) studied the endogenous stages 

 of this species. They are found above the 

 nuclei of the epithelial cells near the tips 

 of the villi. There are apparently two 

 types of first generation schizonts. Much 

 the commoner is a small type about 6 ji in 

 diameter which produces 15 or fewer 

 merozoites each 4 to 6jj, long and Ijj, wide. 

 The other type measures up to 24 by 18 /j. 

 and produces at least 50 merozoites. The 

 first generation merozoites are formed by 

 the end of the second day of infection. 



The second generation schizonts are 

 about 11 to 13/j. in diameter and produce 

 18 to 23 merozoites each 5 to 6(i long and 

 1. 5 to 2jLL wide about 4 days after infection. 



There are a few third generation schi- 

 zonts and merozoites, but most of the sec- 

 ond generation merozoites develop into 

 sexual stages. The macrogametes are 18 

 to 20 ji in diameter when mature, and the 

 microgametocytes are slightly smaller. 

 The microgametes have 2 flagella. Oocysts 

 first appear in the feces late on the fifth or 

 on the sixth day after infection. 



Pathogenesis : This species is only 

 slightly pathogenic in the turkey. Hawkins 

 (1952) found the most severe lesions on the 

 fifth and sixth days after experimental in- 

 fection. The entire small intestine was 

 markedly dilated and the duodenum and 

 anterior jejunum were creamy white when 

 seen thru the serosal surface. The anter- 

 ior half of the small intestine was filled 

 with creamy, yellowish, sticky, mucoid 

 material. The wall of the anterior intes- 

 tine was edematous, but there was little 

 epithelial sloughing. The intestinal tract 

 was virtually normal by the eighth day 

 after infection. 



The only signs Hawkins saw in infected 

 turkeys were a slight tendency to produce 

 somewhat liquid feces and a slight depres- 

 sion in weight gains. 



Immunity; According to Hawkins 

 (1952), turkeys which have recovered 

 from infection are strongly immune to re- 

 infection. 



