Twenty-four 3-5-mo-old battery-hatched bobwhite quail were inoculated orally with 10(5) (ME 49 strain, group A, 6 birds), 10(4) (ME 49 strain, group B, 6 birds), 10(5) (GT-1 strain, group C, 6 birds), and 10(4) (GT-1 strain, group D, 6 birds) Toxoplasma gondii oocysts. One quail in group B died 18 days after inoculation (DAI) due to undetermined etiology. Two quail from group C and 1 quail from group D given GT-1 oocysts died of acute toxoplasmosis 6, 7, and 8 DAI, respectively; numerous T. gondii tachyzoites were found in lesions in visceral tissues. The surviving quail in group A and B were killed 106 DAI and those in groups C and D were killed 60 DAI. Toxoplasma gondii was isolated from pooled tissues of 4 of 5 quail in group B. Brains, hearts, and skeletal muscles from quail in groups A, C, and D were bioassayed individually in mice; T. gondii was isolated from the brains of all 6, hearts of 3, and skeletal muscles of 2 of the 6 quail in group A; from the brains of all 4, hearts of 1, and skeletal muscles of 2 of the 4 quail in group C; and from the brains of all 5, hearts of 1, and skeletal muscles of 3 of the 5 quail in group D. Toxoplasma gondii antibodies were found in sera of all 20 quail killed 60 or 106 DAI. Antibody titers detected in the modified agglutination test using whole tachyzoites were higher than in latex agglutination and indirect hemagglutination tests that used soluble antigens. Antibodies were not detected in a 1:4 dilution of 19 of 20 quail sera in the Sabin-Feldman dye test.