Hematological changes after intermittent hemodialysis in dogs with acute kidney injury are mild and transient

Objective: To evaluate hematological changes in dogs with acute kidney injury caused by different underlying disease processes treated with intermittent hemodialysis (IHD) over 12 to 24 hours after the session. Methods: Client-owned dogs with acute kidney injury treated with IHD from February 2021 through July 2025 were prospectively enrolled in this observational study. Blood was collected from each dog before IHD (T0), after IHD (T1), and 12 to 24 hours after IHD (T2). Hematocrit, RBC count, hemoglobin concentration, reticulocyte count, platelet count, and WBC count were evaluated at all time points. Results: In total, 30 dogs with 82 IHD sessions were included in the study. Median RBC count (X 1012/L) and median hemoglobin concentration (mmol/L) decreased from 4.00 (2.82 to 7.22) and 9.25 (6.60 to 17.20) at T0 to 3.74 (2.39 to 7.04) and 9.00 (5.50 to 16.80) at T1, respectively. Median WBC count (X 109/L) of 19.34 (6.49 to 55.47) at T0 decreased to 17.6 (4.57 to 73.22) at T1 and increased to 20.11 (7.48 to 55.47) at T2. Median platelet count (X 109/L) of 99 (5 to 767) at T0 decreased to 69 (1 to 633) at T1 and increased to 84 (4 to 604) at T2. Conclusions: Hematological changes during IHD were mild and transient. Only the platelet count decreased moderately. Clinical Relevance: Most of the hematological changes did not appear clinically relevant and resolved within 24 hours. However, the moderate decrease in platelet count could potentially predispose dogs undergoing IHD to an increased risk of bleeding.