Introduction

Chronic hepatitis in Labrador retrievers is frequently diagnosed and treated in veterinary practice but the underlying aetiology remains uncertain. Copper-associated chronic hepatitis is a recognised condition in several breeds, most notably the Bedlington Terrier. More recently it has been suggested as a cause of chronic hepatitis in Labrador retrievers in the Netherlands and the USA. The aim of this retrospective pilot study was to quantify hepatic copper accumulation in Labrador retrievers with chronic hepatitis presenting to one institution.

Materials and Methods

Ten Labrador retrievers with chronic hepatitis were recruited from cases presented to the Queens Veterinary School Hospital, Cambridge, between 2003 and 2007. Rubianic acid stain was used to identify copper accumulation in liver biopsies from these patients. Copper accumulation was qualified using a 4 point Likert scale adapted from a previous publication, in which 0 = absence or rare copper positive cells, 1 = few random copper positive cells, 2 = moderate numbers of copper positive cells, 3 = many copper positive cells in all zones.

Results

Qualitative analysis of the biopsies showed a low to moderate hepatic copper accumulation. In 8 out of 10 samples, this accumulation was distributed randomly in all zones of the liver. Using the Likert scale, five dogs were scored as 0, four dogs as 1, and one dog as 2.

Conclusion

These results suggest that toxic copper accumulation is not such a common cause of chronic hepatitis in Labrador retrievers in the United Kingdom as in the Netherlands or the USA. A prospective multicentre study is indicated to look for the prevalence of copper-associated hepatitis in a larger group of Labrador retrievers in the UK. The differences in disease prevalence in the same breed in different countries may reflect geographical genetic differences.