Experimental toxoplasmosis in elk (Cervus canadensis).

One cow elk (approx 4 months pregnant) and one calf elk were each inoculated intraruminally with 10(5) infective oocysts of Toxoplasma gondii. Both animals were seronegative when inoculated, but became seropositive to T gondii. Sabin-Feldman dye test antibody titers in relation to day postinoculation were as follows: 1:1024, 1:1024, and 1:2048 (days 28, 69, and 73) for the calf; 1:2048, 1:128, and 1:128 (days 34, 69, and 73) for the cow; and 1:2546 (73 days after inoculation of the cow) for the fetus. Indirect hemagglutination antibody titers were not detected in sera of the cow or her fetus and remained low (1:64 or lower) in calf sera. Both the cow and the calf remained asymptomatic until necropsy 73 days after they were inoculated. Toxoplasma was isolated in mice and cats after they were inoculated with brain, spinal cord, heart, diaphragm, liver, pancreas, cervical lymph nodes, and intestines of the infected calf; with brain, heart, diaphragm, and skeletal muscles of the infected cow; and with brain, heart, cervical lymph nodes, and spleen of the fetus.