Feed control officials reassert copper concentration guidelines

Maryna / stock.adobe.com

The Association of American Feed Control Officials (AAFCO) sets the standard for both animal feeds and pet foods in the United States and has recently reaffirmed its guidelines for copper concentration in commercial dog foods in response¹ to a viewpoint article² published by the Journal of the American Veterinary Medical Association (JAVMA).

The viewpoint article was researched and written by Sharon Center, DVM, DACVIM; Keith Richter, DVM; David Twedt, DVM, DACVIM; Joseph Wakshlag, DVM, PhD, DACVSMR, DACVIM (Nutrition); Penny Watson, MA, VetMD, CertVR, DSAM, DipECVIM, FRCVS; and Cynthia R. L. Webster, DVM, DACVIM.² Published February 15, 2021, the article gave the AAFCO 3 recommendations regarding copper concentration in commercial dog food. First, reestablish a maximum concentration for copper (Cu) in the AAFCO Dog Food Nutrient Profiles. Second, set the recommended content for Cu in the AAFCO Dog Food Nutrient Profiles to a range from 0.9 mg Cu/1000 kcal of metabolizable energy (ME) (equivalent to 3.6 mg Cu/kg dry matter (DM) in foods containing 4000 kcal ME/kg DM) to a maximum of 1.1 mg Cu/1000 kcal ME (4.4 mg Cu/kg DM). Third, prohibit the use in dog foods of all supplemental sources of Cu except copper oxide.¹

Within a month of the publication of the article, the AAFCO had convened an expert panel to consider the recommendations and the underlying implication that Copper Associated Hepatitis (CAH) in dogs is being caused by the content and supplemental sources of Cu used in dog foods. The panel met 4 times between May 2021 and July 2022.

The panel was composed of¹:

• William Burkholder, DVM, PhD, DACVIM (Nutrition)
• Andrea Fascetti, VMD, PhD, DACVIM (Internal Medicine, Nutrition)
• Angele Thompson, PhD
• Charlotte Conway, MS, PAS
• Dana Tomlinson, PhD
• David Dzanis, DVM, PhD, DACVIM (Nutrition)
• Gail Czarnecki-Mauldin, PhD
• George Collings, PhD, DACAN, CNS, PAS, CFS
• George Fahey, Jr., PhD
• Joseph Wakshlag, DVM, PhD, DACVSMR, DACVIM (Nutrition)
• Karen Donnelly, MS, DVM
• Laura Amundson, PhD
• Louise Caulderwood

From this, the AAFCO concluded that there is a lack of definitive evidence linking copper-associated hepatitis in dogs and the copper content in dog foods. The AAFCO stated in its response, “AAFCO is reluctant to make regulatory recommendations based on implications or associations in the absence of definitive proof of cause and effect and the need for more stringent regulation to correct or prevent a food based caused.”¹

As per the first request from the article, the AAFCO stated in response, “To set a maximum recommended content for Cu in dog foods at this time would be an arbitrary decision, not based on science, without any assurance that the value selected would be protective against CAH as desired.”

As per the second request, the AAFCO stated, “To set the minimum requirement for Cu in diets for dogs to 0.9 mg Cu/1000 kcal of ME (3.6 mg Cu/kg DM) would make the recommended Cu content much smaller than the recommended amounts set by the National Academy of Sciences…Setting the minimum recommended amount in combination with a maximum amount of 1.1 mg Cu/1000 kcal ME (4.4 mg Cu/kg DM) would make the risk of Cu deficiency likely, particularly for dogs in lactation and growth stages of life.”

As per the third request, the AAFCO stated, “Finally, to prohibit the use in dog foods of all supplemental sources of Cu except copper oxide would effectively leave no biologically available sources of Cu for use in dog foods that might require Cu supplementation. Copper oxide is essentially nonbiologically available and will supply nothing of nutritional value to the diet or the animal. At this time AAFCO does not see the need to restrict the use of other sources of Cu in dog foods beyond any restrictions already imposed in their definitions or approvals.”¹

References

1. Response from AAFCO to JAVMA Viewpoint Article of February 15, 2021. Association of American Feed Control Officials. Accessed April 18, 2023.
2. Center SA, Richter KP, Twedt DC, Wakshlag JJ, Watson PJ, Webster CRL. Is it time to reconsider current guidelines for copper content in commercial dog foods? J Am Vet Med Assoc. 2021;258(4):357-364. doi:10.2460/javma.258.4.357