Copper-associated liver disease in dogs: pet food issue?
While most evidence currently points to genetics, it’s possible that copper as a dietary ingredient plays some role.
Some dogs accumulate copper in the liver, resulting in copper storage disease, hepatitis and/or cirrhosis. The numbers are not completely known, but they’re probably less than 1/100 of a percent of the dog population. Initially it was identified with a specific genetic variant in the Bedlington Terrier (autosomal recessive trait). Now there are case reports of other dog breeds affected by various copper storage issues (e.g., Doberman Pinscher, Border Collie, Dalmatian, Corgi, Skye Terrier, West Highland Terrier and White Terrier, German Shepherd, Keeshonden, Boxer and, more recently, Labrador Retriever). Most of these are likely the result of other mechanisms besides the genetic abnormality in Bedlington Terriers. Is it a pet food and ingredient issue or a genetic and pharmacologic matter?
The role of copper in dogs' diets
To start, it is important to understand that copper is an essential mineral in the diet. As a chemical element, copper is described as a transition metal, which means that it easily exchanges electrons with other molecules. It is this ability to play a transitional role in many enzymes involved with physiological processes that makes copper so important and, if left uncontrolled, so potentially damaging.
Much of the dietary copper is not absorbed and is thereby excreted in the feces. The 40–60% that is absorbed relies mostly on active transport mechanisms to cross the small intestinal mucosa, where it is then bound to albumin and shuttled to the liver for further processing. In the liver, copper is repackaged with transport proteins like…