Retrospective Evaluation of Hyperbilirubinemia in Cats and Dogs With Septic Peritonitis or Pyothorax

To characterize serum total bilirubin (TBil) value within 72 h of admission in cats and dogs with septic peritonitis or pyothorax and its relationship with outcome.

Cross-sectional retrospective study.

University teaching hospital.

Sixteen cats with pyothorax, 28 cats with septic peritonitis, 49 dogs with pyothorax, and 86 dogs with septic peritonitis were included. Patients with evidence of hemolytic anemia, hepatic, or biliary disease were excluded.

TBil within 72 h of admission, normalized to a range of 0-4.2 µmol/L (0-0.25 mg/dL) for dogs and 0-5.1 µmol/L (0-0.30 mg/dL) for cats (nTBil), length of hospitalization, and outcome (survived to discharge, euthanized, or cardiopulmonary arrest [CPA]) were recorded in each group of animals. The difference in nTBil between outcome groups was assessed using a Kruskal-Wallis test, and the difference in mortality between normobilirubinemic and hyperbilirubinemic patients was assessed using a χ² test.

The median (range) nTBil and frequency of hyperbilirubinemia were 6.3 (70.8) µmol/L (0.37 [4.14] mg/dL) and 82% in cats with septic peritonitis and 3.1 (120.3) µmol/L (0.18 [7.04] mg/dL) and 56% in cats with pyothorax. The median nTBil was significantly higher in cats that were euthanized or had CPA compared with survivors. Mortality was significantly higher in hyperbilirubinemic cats (48%) compared with normobilirubinemic cats (9%). There was no significant difference in median nTBil between dogs that survived, were euthanized, or had CPA. Mortality was significantly higher in hyperbilirubinemic dogs (45%) compared with normobilirubinemic dogs (28%).

Hyperbilirubinemia is common in cats and dogs with pyothorax and septic peritonitis and is associated with an increased mortality.