THE TELOSPORASIDA AND THE COCCIDIA PROPER 



185 



are absent. The sporocysts are ovoid, 4 

 to 11 by 4 to 6 |u . A sporocyst residuum 

 is present. The sporozoites have one end 

 slender and pointed and the other thick and 

 rounded; they measure 4 to 5 by 2 /j, and 

 lie lengthwise, head to tail, in the sporo- 

 cysts. The sporulation time is 1 to 2 days 

 according to Christensen (1938a) or 3 to 4 

 days according to Balozet (1932). 



Life Cycle : The life cycle of this 

 species has been described by Balozet 

 (1932) in the goat and briefly by Lotze 

 (1954) in the sheep. Their accounts differ, 

 and are given separately below. 



Lotze (1954) found in sheep that the 

 sporozoites enter the epithelial cells ati 

 the base of the glands of Lieberkuehn in 

 the small intestine, where they form 

 schizonts about 300 jj, in diameter contain- 

 ing thousands of merozoites. The sexual 

 stages occur in the epithelial cells of the 

 ileum, cecum and upper part of the large 

 intestine, appearing 15 days or more 

 after infection. 



Balozet (1932a) found in a kid killed 

 39 days after infection that the schizonts 

 were only 15 to 35 /j, in diameter and con- 

 tained only 40 to 200 merozoites. How- 

 ever, these schizonts were found very 

 late in the infection. They were asso- 

 ciated with macrogametes and microga- 

 metocytes, and it is possible either that 

 they may have belonged to a second gen- 

 eration not mentioned by Lotze or that 

 they may have belonged to some other 

 species. 



The prepatent period was found by 

 Shumard (1957) to be 15 days in lambs 

 and by Balozet (1932) to be 10 to 13 days. 



Pathogenesis : This is one of the 

 most pathogenic species of coccidium in 

 sheep. Lotze (1954) found that as few as 

 50,000 oocysts caused diarrhea in a 3- 

 month-old lamb, and as few as 500, 000 

 oocysts caused death. Dysentery was pro- 

 duced in a 2-year-old sheep by inoculation 

 with as few as 1 million oocysts. 



Lotze (1954) found that in lambs the 

 feces became soft in 12 to 17 days after 



experimental infection. They became 

 watery a day or 2 later and remained so 

 for a week or more. In the more heavily 

 infected lambs, the feces contained blood- 

 stained mucus beginning the 15th day after 

 infection or soon thereafter. In those ani- 

 mals which recovered, the feces remained 

 soft for some weeks. 



The lambs with severe diarrhea lost 

 their appetites at first, altho they appeared 

 to drink more. After about a week they 

 drank very little. There was rapid loss of 

 weight at the onset of diarrhea. If the 

 lambs recovered, they gained weight about 

 as rapidly as the controls, but of course 

 had taken a setback in growth. About 2 

 months after severe coccidiosis, the wool 

 began to break off over extensive areas, 

 starting on the flanks; this may have been 

 due to nutritional disturbance caused by 

 the infection. 



The diarrheic feces attracted flies, 

 and affected animals quickly became fly- 

 struck. Some animals which would other- 

 wise have recovered died of flystrike if 

 they were not treated for this condition. 



At necropsy, petechial hemorrhages 

 were found in the small intestine 3 to 7 

 days after infection. The small intestine 

 then became thickened and inflamed. Ex- 

 tensive hemorrhage was present in the 

 posterior part of the small intestine of 

 severely affected lambs by the 15th day. 

 The cecum and upper part of the large in- 

 testine became thickened and edematous, 

 and were hemorrhagic by the 19th day. 

 In heavily infected lambs, vast areas of 

 the posterior part of the small intestine 

 were denuded of epithelium. Thus, one 

 can say that the lesions consisted at first 

 of petechial hemorrhages, followed by 

 thickening, edema and inflammation, and 

 finally by epithelial denudation. The small 

 intestine, especially its posterior part, 

 cecum and upper colon were affected. 



Shumard (1957a) studied a somewhat 

 less pathogenic strain. He reported 

 lowered feed consumption, lassitude, gen- 

 eralized incoordination and slight diarrhea 

 with some bleeding in lambs experimentally 

 infected at 50 days of age with 7 million 



