Cornell study renews scrutiny of copper in commercial dog food

New Cornell-led research is sharpening concern that excess copper in commercial dog foods may be contributing to silent liver injury in older dogs, reviving a debate that regulators and industry have so far resisted settling. A 2025 JAVMA study led by Dr. Sharon Center found lower risk of hepatic copper accumulation in dogs fed copper-restricted diets than in dogs fed copper-replete diets, based on liver samples from 104 geriatric dogs collected between April 2023 and April 2024. The work builds on Center’s earlier 2021 JAVMA viewpoint urging a rethink of current copper guidelines in commercial dog foods, and comes after AAFCO declined in May 2024 to adopt a voluntary “controlled copper” labeling claim for dog food. (pubmed.ncbi.nlm.nih.gov)

Why it matters: For veterinary professionals, the story is less about a single paper than a growing body of evidence that copper-associated hepatopathy may be underrecognized, especially in older dogs without obvious early clinical signs. Current AAFCO nutrient profiles set a minimum copper level for adult maintenance diets, but no upper limit, and veterinary nutrition sources note many commercial diets deliver copper well above the minimum. That leaves clinicians managing a problem that can be difficult to detect early, while pet parents often have limited access to copper data on labels. (aafco.org)

What to watch: Watch for whether the new JAVMA data prompts renewed FDA or AAFCO review, especially around labeling transparency, voluntary claims, or future discussion of a maximum or more tightly defined copper standard. (fda.gov)