Haematological, Biochemical and Acid-Base Changes in Uraemic Dogs Undergoing Intermittent Haemodialysis (2017-2024).

Understanding laboratory variables in animals undergoing haemodialysis is essential for optimizing therapeutic strategies. This study investigated the laboratory variables of uraemic crisis dogs undergoing intermittent haemodialysis (IHD). Medical records of dogs with chronic kidney disease (CKD) in uraemic crisis and those with acute kidney injury (AKI) undergoing IHD between 2017 and 2024 were reviewed. Fifty-eight dogs and 149 sessions were included. A high prevalence of anaemia and hypoalbuminaemia was observed at admission to the IHD, with the prevalence increasing as the number of sessions increased. Among the dogs with AKI and CKD, 84.6% and 78.1%, respectively, had anaemia. Acidaemia, metabolic acidosis and secondary respiratory alkalosis were common and were corrected after the sessions. Among dogs whose pH was within the reference range at admission to IHD, 43.5% exhibited reductions in bicarbonate and PCO2. The prevalence of metabolic acidosis was 40.6% in CKD and 34.6% in AKI. After the sessions, there were decreases (p ≤ 0.001) in RBC, haematocrit, MCHC, platelets, creatinine, urea, phosphorus, plasma proteins and potassium, and increases (p ≤ 0.043) in MCV, pH, HCO3, the anion gap, chloride, sodium and ionized calcium. There was an average decrease in haematocrit of 3.42-5% per session (p < 0.0001). The documented laboratory changes support early therapeutic planning. Acid-base correction and toxin removal highlight the efficacy of IHD, while the progression of anaemia and hypoalbuminaemia requires continued monitoring. Estimating the average decrease in haematocrit per session allows for the prediction of haematocrit decline, enabling more precise planning of priming fluid selection and blood product replacement.