236 



THE TELOSPORASIDA AND THE COCCIDIA PROPER 



of 17 by 11 /i. The sporocyst Stieda body 

 is a button-shaped cap, with a dependent, 

 globular hyaline mass protruding into the 

 interior of the sporocyst. The sporocyst 

 residuum is finely granular. The sporo- 

 zoites are sausage-shaped, not arranged 

 in any particular order in the sporocyst. 

 The sporocyst residuum and sporozoites 

 are enclosed in a membrane, forming 

 more or less of a ball within the sporo- 

 cyst. 



Life Cycle : Unknown. 



Pathogenesis : Unknown. 



Remarks : Levine and Mohan (1960) 

 compared this form with /. lacazei of the 

 English sparrow, which they redescribed. 

 They found that the 2 forms were practi- 

 cally indistinguishable and concluded that 

 the oocysts found in bovine feces were 

 most likely those of /. lacazei and were 

 pseudoparasites of cattle. They calculated 

 that, in a steer which produced about 20 

 pounds of feces per day, the presence of 

 1 oocyst per gram of feces would represent 

 contamination of the feed with about 9000 

 oocysts, assuming that the oocysts were 

 mixed uniformly with the ingesta and 

 passed thru the animal unchanged. Assum- 

 ing again that a flotation was carried out 

 with about 2 g of feces and that about 10% 

 of the oocysts present were recovered, 

 they calculated that every oocyst found 

 might represent an initial contamination 

 of a day's feed with about 45, 000 oocysts. 

 Since Boughton (1933) quite frequently ob- 

 tained counts of 200,000 to 2 million 

 oocysts per gram of dried sparrow feces, 

 they considered it quite likely that spar- 

 row coccidia could be detected in a calf's 

 feces if it ingested only a single fecal 

 deposit from a single sparrow in the 

 course of a day. 



ISOSPORA SUIS 

 BIESTER, 1934 



Host : Pig. 



Location : Small intestine, from the 

 lower third of duodenum to 2 or 3 feet 

 from the ileocecal valve. 



Geographic Distribution : North 

 America (Iowa), USSR (Kazakhstan). 



Prevalence : Unknown. 



Morphology : This species has been 

 described by Biester (1934) and Biester 

 and Murray (1934). The oocysts are sub- 

 spherical to ellipsoidal, becoming more 

 ellipsoidal on sporulation. The oocyst 

 wall is often stretched by the oocysts and 

 pinched in between them. It is smooth, 

 composed of 2 layers, brownish yellow, 

 and 1.5(i thick. A micropyle is absent. 

 The unsporulated oocysts measure 20 to 

 24 by 18 to 21 fi with a mean of 22. 5 by 

 19.4/1. An oocyst polar granule is pres- 

 ent. An oocyst residuum is absent. The 

 sporocysts are ellipsoidal, 16 to 18 by 

 10 to 12 /i with a mean of 16.4 by 11. 2u. 

 The sporocyst wall is double, 0. 7|i thick. 

 The sporozoites are elongate. A sporo- 

 cyst residuum is present. A Stieda body 

 is absent. The sporulation time is 4 days. 



Life Cycle : According to Biester and 

 Murray (1934), /. suis invades the epithe- 

 lial cells of the intestine. Many of these 

 invaded cells migrate to a subepithelial 

 position, but often both the host cells and 

 the parasite appeared to undergo retro- 

 gressive changes and to be desquamated. 



The prepatent period after experi- 

 mental infection is 6 to 8 days, and oocysts 

 continue to be eliminated for about 8 days 

 after a single infective feeding. 



Pathogenesis : According to Biester 

 and Murray (1934), /. sids causes a catar- 

 rhal enteritis. The epithelium of the 

 crypts is destroyed except near the intes- 

 tinal lumen. The substantia propria of 

 the tips of the villi is destroyed, leaving 

 a reticular honeycomb without cells or 

 nuclei. Interstitial inflammation with 

 marked eosinophilic infiltration is present, 

 but there is no gross hemorrhage. 



Diarrhea began about the 6th day af 

 after experimental infection, continued 

 for 3 or 4 days, and was followed by con- 

 stipation. /. suis infections are appar- 

 ently not fatal, but they may retard growth 

 and produce unthriftiness. 



