Serologic prevalence of toxoplasmosis in cattle, sheep, goats, pigs, bison, and elk in Montana.

Serum samples from 2,539 cattle, 649 sheep, 123 goats, 413 pigs, 93 bison, and 56 elk from Montana were examined for antibody to Toxoplasma gondii in the Sabin-Feldman dye test or the modified agglutination test (MAT). Cattle, bison, and elk serum samples were treated with 0.2 M-mercaptoethanol before examination in MAT. In the dye test, 13.2% of sheep, 5.0% of pigs, and 22.7% of goats had antibody at a dilution of greater than or equal to 1:16. In the MAT, 3.2% of cattle, 3.1% of bison, and none of the elk were positive at a dilution of greater than or equal to 1:128.