Hematological findings of free-ranging brown bears (Ursus arctos) from eastern Turkey, obtained by blood film evaluation

Hematology is one of the best population health indicators, and the quickest way to gain insight into some hematological parameters is blood film evaluation. Sometimes, due to the inability to store blood, the unavailability of hematological instruments during field work, or the insufficient amount of blood for complete hematological analysis, blood film evaluation could be the only method for obtaining information about hematological changes. The population of brown bears (Ursus arctos) is often endangered, and is protected as an important integral species of terrestrial communities. Since any baseline hematological data of free-living endangered species are particularly important, the aim of this study was to test the possibility of using blood film evaluation, as the only source of hematological data, for assessment of an animal's hematological and, consequently, health status. Blood films of seventeen brown bears from eastern Turkey were evaluated to assess the morphology of erythrocytes and leukocytes, estimate the total leukocyte count, determine the differential leukocyte count, and look for the presence of cell inclusions or hemoparasites. Rouleaux formations were present in twelve animals, poikilocytosis in four, while parasitic nematodes, microfilariae, were found in nine out of seventeen bears. The results confirmed that blood film evaluation alone could be of use in assessing an animal's hematological status, but for more accurate assessment of health status, more blood parameters need to be analyzed. New findings in the study, such as the presence of rouleaux formations and microfilaria in brown bears from eastern Turkey, have opened the door for further investigation in this field.