[Problems in the demonstration of Toxoplasma gondii in muscle tissue of sheep]

It is a known fact that sheep usually show a high level of infection with the parasite Toxoplasma gondii. Samples of five grams of muscular tissue taken from the diaphragms of forty sheep were digested with trypsin. The digested material was microscopically examined for bradyzoites of Toxoplasma using the Giemsa-staining method and a Toxoplasma-specific immunofluorescence test. In spite of the fact that antibodies were detected with the ELISA in sixty-five percent of the sheep, Toxoplasma could not be identified in any of the samples of muscular tissue.