RESUMEN
A total of 2942 specimens of 15 species of ground rodents and insectova in the Orenburg Region were caught and examined during long-term studies. The investigators detected 7 taxonomic groups of hematozoons: rickettsia (Anaplasma sp., Grahamella sp., Haemobartonella sp.), protozoa (Trypanosoma sp., Plasmodium sp., Piroplasma sp.), and nematodes (Filariidae spp., larval stages). The authors give information on the species composition and infection extensiveness of individual systematic groups of small mammals, the most important morphometric and biological signs of blood parasites, and the specificity of parasite-host relations. The Eversmann hamster was found to have parasitic protozoa of the genera Trypanosoma and Piroplasma, which had not been earlier described in the scientific literature.