Acquired proximal renal tubular dysfunction in 9 Labrador Retrievers with copper-associated hepatitis (2006-2012)

Area of Science:

• Veterinary Medicine
• Hepatology
• Nephrology

Background:

• Copper-associated hepatitis (CAH) is a known liver disease in Labrador Retrievers.
• The link between CAH and proximal renal tubular dysfunction in this breed is not well understood.

Purpose of the Study:

• To characterize the clinical features, histopathology, copper levels, and outcomes of Labrador Retrievers with CAH and renal tubular disease.
• To investigate the association between hepatic copper accumulation and renal dysfunction.

Main Methods:

• Retrospective review of clinical and clinicopathologic data from nine Labrador Retrievers with biopsy-confirmed CAH and renal glucosuria.
• Assessment of hepatic and renal copper concentrations using rhodanine staining or atomic emission spectroscopy.
• Histopathological examination of renal tissues.

Main Results:

• All affected dogs had increased hepatic copper concentrations, and renal specimens showed elevated copper levels.
• Renal tubular changes including vacuolization, degeneration, and regeneration were observed.
• Clinical signs included polyuria, polydipsia, elevated serum bilirubin, and in some cases, hyperchloremic metabolic acidosis and paradoxical alkalinuria.

Conclusions:

• Labrador Retrievers with CAH can exhibit clinical and laboratory signs of renal tubular dysfunction due to increased renal copper.
• The presence of renal glucosuria and elevated ALT in a Labrador Retriever may indicate CAH, even if renal disorders are rare.
• Despite potential indicators of advanced disease, long-term survival is achievable with appropriate management.