Did a Flawed Hill’s Pet Food Copper Paper Influence the AAFCO Vote?

On May 30, 2024 the AAFCO Pet Food Committee held a virtual meeting in which a vote was taken to pass or fail a proposed voluntary limited copper pet food claim.

The proposal was:

“Low Copper. A dog food that bears on its label the claim ‘low copper’, ‘low in copper’, or words of similar designation shall:
1) Be substantiated as nutritionally adequate for one or more life stages in accordance with Regulation PF7; and
2) Contain a maximum of no more than 15 mg copper/kg DM and no more than 3.75 mg copper/1,000 kcal of metabolizable energy; and
3) Bear on its label in the Guaranteed Analysis in accordance with Regulation PF4 a guarantee for the maximum amount of copper in the dog food.“

All this language simply means – if approved – a pet food can voluntarily implement a maximum copper level (it wouldn’t be required – it is voluntary) and state ‘Low in Copper’ on their label to alert pet owners.

But, AAFCO voted against it, refusing to establish a voluntary limited copper pet food.

A few months earlier, in January 2024, a paper was published in the Journal of the American Veterinary Medical Association (JAVMA) that claimed their research indicates pet “liver copper concentrations” were not problematic. Three of the four authors are employees of Hill’s Pet Food. Dr. Leslie Hancock – co-author and Hill’s pet food chief medical officer stated “although there is an increase in copper concentrations, it is not clinically significant.”

The paper – certain to have influenced the AAFCO vote – claimed the current regulations allowing any level of copper (above minimum) in pet food “are not resulting in hepatic copper toxicity.”

But…

The publication Retraction Watch states JAVMA received seven letters “crying foul” regarding the validity of the Hill’s paper. Of significance, the letters crying foul with the paper began “within weeks” of the January 2024 publication date – well before the May 2024 AAFCO vote.

The letters challenging the validity of the paper were forwarded to Dr. Leslie Hancock (Hill’s veterinarian and paper co-author). And…the paper was retracted on May 21, 2024 (about 1 week prior to AAFCO’s vote). Hill’s veterinarian Dr. Hancock stated:

“With deep regret, we acknowledge that during our data analysis, we did not possess all the necessary information, leading to an oversight when interpreting the results.”

What some said about the Hill’s paper:

A veterinarian from California – Dr. Keith Richter – stated “The authors state the objective of this study is to ‘examine the effects of age, sex, breed, liver histopathology, and year of death on liver copper concentrations in dogs fed commercial dog foods’. We believe the real underlying objective was to prove that commercial dog foods are not responsible for increasing hepatic copper concentrations and copper associated hepatopathies.”

Dr. Daniel Langlois – an associate professor at Michigan State University’s College of Veterinary Medicine told Retraction Watch “This was a massively flawed study.”  “The authors’ conclusions were also completely overstated, and they immediately disseminated their results and conclusions to a number of veterinary news outlets with the final message being that regulations for dietary copper supplementation are not involved in the etiology of copper-associated hepatopathy in dogs.”

Again, these challenges from the veterinary community about this paper were happening BEFORE AAFCO voted to squash voluntary restricted copper pet food label claims. The paper was retracted about one week prior to the important AAFCO vote.

Who knew the paper was being challenged?

The paper co-author/Hill’s veterinarian Dr. Leslie Hancock knew. As stated by Retraction Watch, the letters “crying foul” were forwarded to Dr. Hancock ‘within weeks’ of publication.

Did the Hill’s veterinarian alert AAFCO or FDA to the challenges her paper had received or the retraction prior to the vote?

We don’t know. AAFCO is a private organization, we cannot file a Freedom of Information Act request for more information.

But we do know that Dr. Hancock had easy access to AAFCO voting members IF she chose to do the right thing. Dr. Hancock participated in the AAFCO working group discussing the topic of copper levels in pet food prior to the AAFCO vote. With her participation in this AAFCO working group, Dr. Hancock had working relationships with AAFCO members and FDA. Which means she could have easily alerted them – prior to the vote – that the study was flawed.

Or did AAFCO and FDA know the paper claiming copper levels in pet food are not the foundation of liver disease in pets was flawed, and they voted against it anyway?

Again, we do not know.

Either way, pet owners deserve this topic to be opened up again at AAFCO. We sent the following message to the AAFCO Pet Food Committee:

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On behalf of pet food consumers, we are requesting the AAFCO Pet Food Committee to nullify the recent vote regarding voluntary controlled copper pet food label claim. As foundation for this request, is the retracted science submitted by a Copper Claim Workgroup member – Dr. Leslie Hancock.

Dr. Hancock and others published the paper “Sixteen years of canine hepatic copper concentrations within normal reference ranges in dogs fed a broad range of commercial diets” in January 2024 (in JAVMA). However after multiple members of the veterinary community challenged the validity of her research, the paper was retracted on May 21, 2024.

We assume that during Dr. Hancock’s participation in the AAFCO Working Group, she based much/some of her input to the group on the flawed study. Thus, her participation in the working group could have influenced voting members – again based on flawed science. We request that the members of the Pet Food Committee be informed of the retraction of Dr. Hancock’s study, be provided with the letters from the veterinary community who challenged the study, and another vote to be taken.

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One more thing…

At the summer 2023 AAFCO meeting, there was a veterinarian that argued and argued with the Pet Food Committee against any restriction of copper in pet food. She argued there is no science to validate a maximum level for copper, she argued that pet owners would be confused at the ‘low in copper’ claim and put their pets in danger, she argued that there is no evidence that any pet has been sickened by copper levels in pet foods, she argued that manufacturers and AAFCO would be sued for causing pets to be deficient in copper.

Guess who that arguing veterinarian was?  Dr. Leslie Hancock of Hill’s Pet Food, co-author of the flawed paper.

The next AAFCO meeting will be held in early August. We will keep pet owners posted to any discussions on this topic.

Wishing you and your pet(s) the best,

Susan Thixton
Pet Food Safety Advocate
Author Buyer Beware, Co-Author Dinner PAWsible
TruthaboutPetFood.com
Association for Truth in Pet Food

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