Significant disease is often present when bilirubin is increased enough to cause icterus (usually, >34 µmol/L [2 mg/dL]) in veterinary patients. Prehepatic (eg, immune-mediated hemolytic anemia), hepatic (eg, copper-associated hepatopathy), and posthepatic (eg, extrahepatic biliary obstruction) differentials should be included in initial assessment of hyperbilirubinemic patients.
This retrospective study described clinical presentation and outcome of dogs (n = 115) with hyperbilirubinemia from 2 referral practices in Australia and sought to identify factors associated with survival. Clinical signs at presentation were nonspecific; vomiting, anorexia, lethargy, and fever were most common. Median patient age was 9 years, but a wide range (10 months to 16 years) was represented. Most dogs underwent advanced imaging (ie, abdominal ultrasonography [66.9%], abdominal CT scan [10.4%]). Liver biopsy (21.7%), fine-needle aspiration (11.3%), and tissue or bile culture (13.9%) were also performed.
Hepatic icterus was most common (44.3% of cases), followed by posthepatic (36.5%) and prehepatic (15.7%) icterus. Fifty-three dogs (46.1%) survived to discharge, and median survival time for all dogs was 40 days. Prehepatic hyperbilirubinemia (eg, due to immune-mediated hemolytic anemia, posttransfusion hemolysis, tiger snake envenomation) was associated with a significantly higher risk for death compared with hepatic or posthepatic conditions.
Serum bilirubin ≥60 µmol/L (3.5 mg/dL) was associated with significantly decreased median survival time. This result supports the importance of hyperbilirubinemia in patient assessment and prognosis and suggests hyperbilirubinemia should be discussed with pet owners, regardless of underlying cause or disease process.
