NATURAL INFECTIONS BY CRYPTOSPORIDIUM SP IN FARM-RAISED DUCKS AND GEESE

Modified Ziehl-Neelsen staining and an indirect immunofluorescent assa y appeared to be equally useful for monitoring natural infections with Crytosporidium sp. in farm-raised Pekin ducklings and Danish goslings . In 73 of 128 ducklings, and in 44 of 74 goslings, Cryptosporidium sp . were detected. Tissues from the bursa of Fabricius are most frequent ly positive in both species. The presence or absence of the parasite c ould not be correlated with clinical signs or lesions and/or poor perf ormance of the birds. Oocysts from ducklings could not be transmitted to suckling mice but were infectious for ducklings. Oocysts from calve s were infectious for mice but not for ducklings. These findings suppo rt the view that mammals and birds have different Cryptosporidium spp.