244 



THE TELOSPORASIDA AND THE COCCIDIA PROPER 



Morphology : The oocysts are ellip- 

 soidal, 10 to 13 by 9 to 11 (i. The oocyst 

 wall is thick, colorless, composed of an 

 outer thin, transparent layer and an inner 

 thicker layer. A micropyle is absent. 

 The sporozoites are curved, with one end 

 rounder and broader than the other, about 

 10 fi long and 3. 5fx wide at the larger 

 end. The oocyst residuum is large, 

 usually spherical. The sporulation time 

 is 1 day. 



Life Cycle : According to Allen 

 (1936), the endogenous stages are found 

 in the mucosal and submucosal cells. 

 There are at least 3 asexual generations. 

 The first generation schizonts are rela- 

 tively small, about 12 by Sfi, and contain 

 relatively few, small merozoites. The 

 later schizonts measure about 15 to 16 by 

 14 to 15ji and contain more and larger 

 merozoites than the first generation ones. 

 Schizogony continues long after the forma- 

 tion of gametes. 



The first microgametocytes appear 

 2 days after infection. They measure 

 about 7. 5 by 6jn and produce a large num- 

 ber of tiny microgametes. The macro- 

 gametes are somewhat irregular in shape. 

 Oocysts first appear in the feces 6 days 

 after infection. 



Pathogenesis : According to Allen 

 (1936), T. peniiciosa is highly pathogenic 

 for ducklings. All of 7 experimentally 

 infected, week-old ducklings died. 



Affected birds stop eating, lose 

 weight, become weak and cry continuously 

 as if in distress. At necropsy, inflamma- 

 tion and hemorrhagic areas were found 

 thruout the small intestine and especially 

 in its upper half. The intestinal wall was 

 thickened, and round, white spots were 

 visible thru its serosal surface. In se- 

 vere cases the lumen was filled with blood 

 and often contained a cheesy exudate. The 

 intestinal epithelium sloughed off in long 

 pieces, sometimes forming a tube which 

 could easily be lifted out. 



TYZZERIA ANSERIS 

 NIESCHULZ, 1947 



Hosts : Domestic goose, white- 

 fronted goose {Anser albifrons), blue or 



snow goose (A. caerulescens), Ross's 

 goose (A. rossi), Canada goose {Bfanla 

 ca)iadensis), Atlantic brant (B. bernicla 

 hrola), whistling swan (Olor colunibianus), 

 lesser scaup duck {Nyroca affinis). 



Location : Small intestine. 



Geographic Distribution : North 

 America, Europe. 



Prevalence : This species is appar- 

 ently rare in domestic geese, having been 

 reported in them only by Nieschulz (1947) 

 in Holland and by Farr and Wehr (1952) in 

 Maryland. It is common, however, in 

 wild geese, and has been found in all the 

 species from which coccidia have been re- 

 ported and from all 6 North American fly- 

 ways (Hanson, Levine and Ivens, 1957). 

 It is most likely a parasite of wild geese 

 which occasionally occurs in domestic 

 ones as the result of accidental contam- 

 ination. 



Morphology : The oocysts were des- 

 cribed by Levine (1952). They are ellip- 

 soidal, 10 to 16 by 9 to 12jLL with a mean 

 of about 13 by l\ [i . The oocyst wall is 

 smooth, colorless, about 0.6(i thick, and 

 usually appears to be composed of a sin- 

 gle layer altho in some oocysts a second 

 inner line is visible; this may perhaps be 

 a membrane which has pulled away from 

 the wall. A micropyle is absent. The 

 sporozoites are banana-shaped. The 

 oocyst residuum is large, irregular, gran- 

 ular, and often surrounded by the sporo- 

 zoites. 



Life Cycle : Unknown. 



Pathogenesis : Unknown in very 

 young birds; negligible in adults. 



COCCIDiOSIS IN DUCKS AND GEESE 



Our knowledge of the coccidia of 

 ducks and geese is extremely deficient. 

 Except for renal coccidiosis of the goose 

 caused by E. Irmicata, coccidiosis ap- 

 pears to be of little importance in these 

 birds, and coccidia have seldom been re- 

 ported from them. A few outbreaks of 

 intestinal coccidiosis have been reported, 



