Serum Prevalence of Bears in the Russian Far East to Different Pathogens

The serum prevalence of brown (Ursus arctos) and Asiatic black bears (Ursus thibethanus) to 14 different pathogens is analyzed; seropositive bears to ten different pathogens are found. The serum prevalence is at the maximum for Candida sp., pseudorabies virus and Dirofilaria sp. Species-specific differences in the serum prevalence to different pathogens are observed for Trichinella sp. and Toxoplasma gondii, but seropositive individuals are observed only among brown bears. These variations can be explained by differences in the feeding behavior of the brown and Asiatic black bears and the frequency of contacts with the Amur tiger and its kills.