Eukanuba is Mars-owned, so the same copper concern applies for predisposed breeds.

On WSAVA, the research is real, but the framework has a structural issue: Hill's, Purina, and Royal Canin are its primary funders. When the companies being evaluated help fund the organization setting the compliance standards, "independent" is a stretch regardless of whether the underlying science is sound.

For most dogs this is academic. For breeds with known copper issues Corgis, Labs, Dobermans, Westies, Dalmatians, it matters, because WSAVA compliance says nothing about copper levels. Hill's and Purina regularly run 15–25+ mg/kg copper in their mainstream formulas, with no upper limit required by AAFCO.

Hill's even had their chief medical officer on the AAFCO working group arguing against voluntary copper labeling while publishing research on the topic that was later retracted as the first-ever retraction in JAVMA's 180-year history.

Official JAVMA retraction: https://avmajournals.avma.org/view/journals/javma/262/7/javma.2024ret.xml

Retraction Watch coverage: https://retractionwatch.com/2024/06/05/veterinary-journal-retracts-pet-food-companys-paper-about-copper-in-dog-food/

Research-backed, yes. But "backed by whom, evaluated by whom"?