Survey for toxoplasmosis in wild and domestic animals from Norway and Sweden.

Fifty-nine of 1250 (4.7%) wild and domestic animals from Norway and Sweden had positive dye-test titers (greater than or equal to 1:8) for antibody against Toxoplasma gondii. A dye-test titer of 1:8 (30-40 i.u.) or higher was detected in 3 of 732 small rodents (0.4%), 21 of 87 domestic cats (24%), 9 of 29 red foxes (Vulpes vulpes) (31%), 2 of 2 domesticated arctic foxes (Alopex lagopus), 12 of 99 red deer (Cervus elaphus) (12%), 5 of 8 roe deer (Capreolus capreolus) (63%) and in 7 of 34 wild rabbits (Oryctolagus cuniculus) (21%). Antibodies were not found in 29 shrews (Sorex spp.), 127 gulls (Larus spp.), 4 terns (Sterna sp.), 10 skuas (Stercorarius sp.) 68 domestic reindeer (Rangifer tarandus) and 21 wild reindeer. Histologic examination of brain tissue from another 51 wild rabbits on which serological data were not available, did not reveal cysts. Sero-conversion was not observed in laboratory mice inoculated with the same material. Infection with T. gondii was confirmed in two of the three sero-positive small rodents using a FA-technique. Cysts were not detected in the brains of another 55 rodents, of which 26 were sero-negative and 29 were not tested serologically.