By using sandwich ELISA, E. granulosus coproantigens could be detected during the initial phase of the infection in dogs experimentally infected with this cestode. In dogs, inoculated with protoscoleces from only one cyst, recovered worms showed almost same developmental stage and the coproantigens detected in samples from these dogs showed a similar pattern. It is suggested that the release of E/S antigens in the feces may be synchronized depending on the developmental stage.

Antibody response of dogs against E. granulosus antigens was also examined. However, antibody levels of dogs infected with a large number of worms did not rise, while only one dog infected with few worms showed apparently high antibody levels.

This sandwich ELISA was also used for the diagnosis of 59 dogs in Uruguay. Dogs were treated with arecoline hydrobromide and the excreted parasites were identified. The diagnostic probability of true-positive cases was unexpectedly low (40%) and that of false-positive ones was 14%.