Acute postoperative hypophosphatemia is a potential sequela following hepatectomy in dogs

To describe posthepatectomy hypophosphatemia in dogs and evaluate whether the extent of hepatectomy was associated with postoperative hypophosphatemia.

This was a retrospective, observational study of dogs that underwent hepatectomy from January 1, 2019, through December 15, 2025, with serum phosphorus concentrations recorded preoperatively and within 72 hours postoperatively. Dogs with comorbidities or complications expected to influence serum phosphorus were excluded. Data included extent of hepatectomy (division/subdivisional) and change in serum phosphorus concentration (ΔP). Phosphorus and the proportions of dogs with recorded hypophosphatemia were compared between dogs undergoing division hepatectomy and subdivisional hepatectomy using the Mann-Whitney test and Fisher's exact test, respectively.

42 dogs were included (19 subdivisional, 23 division hepatectomy). Median ΔP was -0.8 mg/dL (range, -3.8 to 3.4). ΔP was greater in dogs with division hepatectomy (-0.9 mg/dL; range, -3.8 to 3.4) than subdivisional hepatectomy (-0.5 mg/dL; range, -1.7 to 1.2). Seven of 42 dogs (16.7%) developed postoperative hypophosphatemia at a median of 20 hours (range, 16 to 43); all dogs had undergone division hepatectomy (7 of 23 [30.4%]). Three dogs were treated with IV potassium phosphate. No dogs (0 of 19 [0%]) with subdivisional hepatectomy had recorded hypophosphatemia.

Hypophosphatemia can arise in dogs after liver resection, primarily following division hepatectomy or greater. There was an overall decrease in phosphorus for both divisional and subdivisional hepatectomy groups.

Routine assessment of phosphorus following hepatectomy may be considered to minimize the risk of consequential hypophosphatemia.