Hepatic 64Cu excretion in Dobermanns with subclinical hepatitis

To investigate whether Dobermanns have impaired copper excretion an intravenous radioactive copper isotope (64Cu) was used as a tracer. Five patients and eight normal dogs (5 normal Dobermanns and 3 Beagles) were studied. The five female Dobermann patients had a subclinical hepatitis and an increased hepatic copper concentration (median 822 mg/kg, range 690–1380 mg/kg dry matter). The normal dogs, five Dobermanns and three Beagles, had no abnormal liver histopathology and hepatic copper concentrations were considered normal (Dobermanns; median 118 mg/kg, range 50–242 mg/kg dry matter; Beagles; median 82 mg/kg, range 50–88 mg/kg dry matter). Cholestasis was excluded in all dogs by means of a 99mTc-Bis-IDA hepatobiliary scintigraphy. Plasma clearance of 64Cu was comparable in all dogs with no statistically significant differences. The excretion of 64Cu into the bile, although not statistically significant, was less for the Dobermanns with subclinical hepatitis compared to the normal dogs. The findings suggest that impaired copper excretion may play a role in the aetiology of chronic hepatitis in the Dobermann.