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Another Paper Questioning The Safety Of Copper Levels In Dog Food


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Another Paper Questioning The Safety Of Copper Levels In Dog Food

This is the second scientific paper that questions AAFCO’s decision to have no maximum level of copper in pet food

Susan Thixton

February 9, 2021

Another Paper Questioning The Safety Of Copper Levels in Dog Food – Truth about Pet Food


This is the second scientific paper that questions AAFCO’s decision to have no maximum level of copper in pet food.

Published in the Journal of American Veterinary Medical Association is the new paper “Is it time to reconsider current guidelines for copper content in commercial dog foods?” The paper determines – yes, it is time for AAFCO to reconsider the current guidelines for copper in dog food.

The paper gives opinion, that an increase in liver disease in dogs occurred after 1997 when AAFCO changed an approved copper supplement in dog food; “Over the past 15 to 20 years, we have seen what we believe to be an increased incidence of copper-associated hepatopathy in dogs. …our collective clinical opinion is that the incidence of this disease began to increase after the 1997 development of new guidelines for copper content in dog foods.”

As background, the study provides this information regarding the 1997 AAFCO changes to copper amounts in pet food:

In 1997, the AAFCO recommendation regarding copper in commercial dog food was revised on the basis of a study that evaluated the relative bioavailability of feed-grade copper oxide, compared with that of copper sulfate. In that study, dogs fed a diet to which copper oxide (1.7 or 4.7 mg Cu/1,000 kcal) had been added had decreases in serum copper and hemoglobin concentrations within 16 weeks, which the authors interpreted to reflect insufficient copper intake. In contrast, dogs fed a diet to which copper sulfate had been added at a rate of 1.9 mg Cu/1,000 kcal did not develop anemia, and those fed a diet to which copper sulfate had been added at a rate of 2.7 mg Cu/1,000 kcal did not have any decrease in serum copper concentrations. Importantly, the baseline diet fed to dogs in that study was not specified, and a full description of the study details has not been published, to the authors’ knowledge. Nevertheless, and despite the fact that there had been no evidence of widespread clinical copper deficiency in dogs prior to this study, recommendations for dietary sources of copper were subsequently modified. Specifically, a recommendation was made to replace feed-grade copper oxide in canine diet formulations with more bioavailable forms of copper, such as copper sulfate.”

Interpretation of the above: in 1997, AAFCO deleted a previously approved copper supplement (copper oxide) and approved a new copper supplement (copper sulfate) that was “more bioavailable” based on incomplete science.

And it gets worse…from the paper:

The 2007 AAFCO Canine Nutrition Expert Subcommittee deleted the maximum copper concentration from the adult maintenance nutrient profile for commercial dog foods and did not declare a new upper tolerability limit.”

Which means that not only did AAFCO approve a more bioavailable copper supplement for dog food without lowering the minimum amount, shortly after the organization also deleted the maximum level requirement of copper allowed in dog food. Prior to 2007, AAFCO Nutrient Profiles included a maximum allowed level of copper as 71 mg per 1,000 kcal in dog food. After 2007 (to present day), AAFCO has allowed ANY level of copper in dog food above a minimum of 1.83 mg per 1,000 kcal.

The results of these decisions by AAFCO are what this paper and a previous paper in 2019 believes is an increase of copper storage liver disease in dogs.

Should AAFCO have the responsibility to make nutrient decisions in pet food?

After the 2019 paper evidencing a link to copper storage disease in dogs to copper sulfate with no maximum level established, TruthaboutPetFood.com sent the study to the AAFCO Pet Food Committee. AAFCO never responded.

The 2021 AAFCO Pet Food Committee consists of 21 voting members. Per our knowledge, only 3 of the Pet Food Committee’s voting members hold a science degree; William Burkholder – Veterinary Medical Officer FDA Center for Veterinary Medicine (Dr. Burkholder is a board certified veterinary nutritionist), Srinu Chigurupati – Veterinary Medical Officer FDA (Dr. Chigurupati is a veterinarian), Charlotte Conway – Animal Scientist FDA Center for Veterinary Medicine.

The remaining 18 members of the existing AAFCO Pet Food Committee – who all have authority to vote to approve or deny a pet food ingredient or nutrient change – are all ‘feed’ officials with varying qualifications. Such as: Kristen Green is a “Feed Regulatory Specialist” in Kentucky – her qualifications appear to be regulations, not science. And George Ferguson is a “Feed Administrator” in North Carolina – his qualifications appear to be in administrative duties, not science. While these and the remaining feed officials on the AAFCO Pet Food Committee might be very skilled at their jobs overseeing regulations – should they hold the responsibility to make nutrient decisions in pet food?

Two scientific papers have documented an increase in copper storage disease in dogs – both papers point to a failure of AAFCO nutrient profiles as the probable cause (no maximum level of copper established in regulation). Yet AAFCO and FDA hasn’t mentioned a word about the scientific evidence presented – instead they chosen to ignore it…ignore an increase in pet deaths directly linked to high levels of copper in dog food.

Here is a link to the full list of members to AAFCO’s Pet Food Committee: The Association of American Feed Control Officials > Regulatory > Committees > Pet Food. Feel free to contact any member of the Committee and ask them why there is no maximum level for copper in dog food. Ask them why the 2019 paper was ignored, and if they plan on ignoring this 2021 paper too.

With this and so many other issues, we have sufficient evidence the current system of pet food regulation is failing our pets. How many pets will have to suffer and/or die before pet owners are provided with a pet food regulatory system based on unbiased science and proper enforcement of law?

Wishing you and your pet(s) the best,

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


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