Two hundred sixty-five black bears (Ursus americanus) from northcentral Idaho were examined serologically over a five-year period for antibodies against selected infectious disease agents. The number of positive serum samples per number of sera tested and percent positive for each infectious agent is: tularemia, 65/340 (19); brucellosis, 18/332 (5); toxoplasmosis, 23/303 (8); leptospirosis, 2/196 (1); trichinosis, 16/122 (13); Q-fever, 13/210 (6); St. Louis encephalitis, 3/340 (1); western equine encephalitis, 4/334 (1); Rocky Mountain Spotted Fever, 6/282 (2). Black bears may serve as an indicator for infection in other wildlife, domestic animals and humans in the area.
