This study focused on observation of seasonal changes of selected haematological parameters in Trachemys spp. The experiment involved 6 turtles of the same species and approximately the same size. From September 2017 to December 2018 on a monthly basis, the samples of turtle blood were collected and blood smears were made, which were subsequently evaluated by the light microscopy. During the period of observation, we focused on the changes in the percentage of individual types of cells in a leucogram. The most significant differences in the percentage of leukocytes were observed during hibernation and during the summer period. The blood profiles revealed that the most heterophilic granulocytes were most abundant in the summer, when their values reached 50 % of the leukocytes. Significant changes in the percentage of heterophilic and basophilic granulocytes occurred during the period of hibernation. The number of heterocytes during hibernation decreased to 30 %. On the contrary, the number of basophils increased significantly to 33 %. Eosinophilic granulocytes, lymphocytes, and monocytes did not show such notable changes. The results of the study demonstrated that in turtles of the Trachemys genus, changes in their leuco-grams occurred during the period of hibernation. These changes are important for the evaluation of health condition of the turtles, determination of the prognosis and the treatment.
