With the exception of very specific cases of copper accumulation in the liver (specific to only a few breeds) and aflatoxins accumulating from eating moldy corn (also a rare occurrence), the vast majority of case of chronic active hepatitis in dogs are autoimmune in origin. (web-dvm.net)
By mapping candidate single nucleotide polymorphisms (SNPs) and performing detailed functional analyses, they show that mutations in the Wilson disease gene ATP7B are associated with copper accumulation in the liver, validating the use of these dogs as a model for the human disease. (sciencedaily.com)
Intriguingly, Dr Fieten and colleagues also found that mutation of a second copper transporter gene, ATP7A, protected dogs against hepatic copper accumulation. (sciencedaily.com)