Experimental studies on the life cycle of a renal coccidium of lesser snow geese (Anser c. caerulescens)

Coccidia-free, artificially reared lesser snow geese and ducks (Anas strepera, A. platyrhynchos and A. discors) were inoculated orally with sporulated oocysts of Eimeria sp. from the ureter of heavily infected juvenile lesser snow geese from Manitoba, Canada. In the experimentally infected geese, oocysts were passed in the faeces beginning on day 9 plus or minus 1 after inoculation and continuing for a further 34 to 35 days; peak oocyst production occurred on days 11 and 12. The morphology of the oocyst is described and illustrated. The experimentally infected geese showed mild diarrhoea, slight anorexia, polydipsia and increased salt gland discharge. The kidneys were enlarged, pale and covered with 1 to 2 mm whitish nodules which contained many oocysts, as did the ureters and lumina of renal tubules. No patent infections were produced in the ducks. Domestic geese infected with similar numbers of oocysts as the lesser snow geese passed few oocysts, beginning on day 11 and continuing for a few days. The likelihood that the parasite is E. truncata needs confirming..