Experimental toxoplasmosis in pheasants (Phasianus colchicus)

Sixteen 6-mo-old battery-reared ring-necked pheasants (Phasianus colchicus) were inoculated orally with 10(5) (group A, ME 49 strain, five birds), 10(4) (group B, ME 49 strain, six birds) and 10(4) (group C, GT-1 strain, five birds) Toxoplasma gondii oocysts. The pheasants in groups A and B remained clinically normal. One of the pheasants in group C died 19 days after inoculation (DAI); T. gondii was found in histological sections of brain and heart and encephalitis, myocarditis and enteritis were the main lesions. Toxoplasma gondii was isolated by bioassays from pooled tissues of five of six pheasants in group B killed 36 DAI. Toxoplasma gondii was isolated from the brains, hearts and skeletal muscles of each of the four pheasants inoculated with the GT-1 strain (group C), and from the brains of four, hearts of three and skeletal muscles of four of five pheasants inoculated with the ME 49 strain (group A). All pheasants developed high (1: 1,600-1:25,600) antibody titers to T. gondii in the modified agglutination test (MAT) 36 to 68 DAI. Antibody titers detected with the MAT were higher than those detected in the indirect hemagglutination and latex agglutination tests. Antibodies were not detected in 1:4 dilution of pheasant sera with the Sabin-Feldman dye test.