M.B. Yessenaliyeva1*, Z.B. Tungushbayeva1, K.O. Sharipov2 1Abai Kazakh National Pedagogical university, Almaty, Kazakhstan 2Aitkhozhin Institute of Molecular Biology and Biochemistry, Almaty, Kazakhstan *Corresponding author’s email: meirimbakytkhankyzy@gmail.com Received: 11 August 2025 / Revised: 5 November 2025 / Accepted: 21 November 2025 / Published Online: 23 December 2025 Abstract Cadmium is a known environmental toxicant that affects various physiological systems, including hematopoiesis. This study aimed to assess the dose-dependent effects of cadmium on peripheral blood parameters in Wistar rats. Twenty four animals were assigned to four groups: control, permissible exposure limit (PEL), subtoxic and acute exposure. Cadmium was administered via drinking water over 28 days. Hematological analysis showed no statistically significant changes in the PEL group. However, rats exposed to subtoxic and acute doses exhibited marked reductions in red blood cell count, hemoglobin level, hematocrit and erythrocyte indices, demonstrating the development of microcytic hypochromic anemia. A biphasic pattern in leukocyte count was observed: leukocytosis in the PEL group and leukopenia in higher dose groups, suggesting immune modulation depending on dose. A significant decline in platelet counts was recorded under high-dose exposure, reflecting impaired thrombopoiesis. The results confirm that cadmium causes hematological alterations at doses exceeding environmental limits. Peripheral blood indices, particularly erythrocyte and platelet parameters, proved to be sensitive indicators of cadmium – induced toxicity. These findings emphasize the importance of including hematological screening in toxicological evaluations and ecological monitoring systems. Keywords: Cadmium, Hematotoxicity, Wistar rats, Biomarker, Environmental toxicology | 
