抄録
Two experimental cross-infections of beagle puppies with the Giardia intestinalis are described. In each experiment three littermates at the age of 18 and 24 days were included. In each group, two puppies were orally inoculated with cysts, the third animal served as a control. One of the inoculated puppies in each group was immunosuppressed by dexamethasone. In the first experiment, an isolate from lamb was used for the inoculations at a dose of 20,000 cysts pro toto, in the second experiment an isolate from pig at a dose of 30,000 cysts pro toto. Feces were examined regularly for Giardia cysts, blood samples were analyzed for specific anti-Giardia IgG and IgM antibodies by means of the IFAT technique and parameters of non-specific immunity were determined. The attempt at cross- transmission failed even in markedly immunosuppressed puppies. Neither release of cysts nor seroconversion of circulating specific antibodies were detected. We assume that cross-infection of dogs can occur only under exceptional circumstances. Dogs do not represent significant source of Giardia intestinalis infection for man, even during their mutual close coexistence.
