Copper in Dog Food: A Risk‑Based Guide to Diet and Copper Storage Disease in Dogs

Copper in dog food has become a hot topic, and for good reason. Modern diets often contain far more copper than dogs actually need, and research now shows that genetics and diet interact to drive copper‑associated hepatopathy (CuAH) in many breeds and mixes, not just the “usual suspects.” At the same time, copper is an essential nutrient, so over‑restricting it without a plan is not the answer.

More and more concerned dog owners are asking about proactive copper management in dogs who appear “healthy,” especially now that Embark and other DNA panels are flagging copper toxicosis variants in breeds beyond the classic copper‑associated list. When a test result suddenly says “notable for copper toxicosis,” owners quite reasonably want to know what to feed, even before there is clinical liver disease. It is essential to provide guidance that is evidence‑based and balances nutritional requirements with real‑world choices, rather than anecdotal concerns.

The goal here is to present a simple, risk‑based way to think about diet selection for dogs that do NOT (yet) have diagnosed copper‑associated hepatopathy. The approach is grounded in published work from Dr. Hille Fieten’s group at Utrecht University, Dr. Sharon Center and colleagues at Cornell, and recent copper‑nutrition reviews and consensus statements. The “tier” labels here are an educational tool for pet owners and primary‑care veterinarians, but the underlying concepts come directly from this body of veterinary science (Fieten et al. 2015; Fieten 2020; Amundson & Center 2023; ACVIM consensus 2019; Lidbury 2023).

Who are Center, Fieten – and why Soul Dog Synergy?

Dr. Sharon Center (Cornell University) is a James Law Professor of Internal Medicine and one of the most widely recognized experts in small‑animal hepatology worldwide. Her work spans liver disease in both dogs and cats, including chronic hepatitis, copper‑associated hepatopathy, and the use of bile acids and other tests to assess liver function. Over the last decade she has also been a key voice drawing attention to the rising incidence of dietary‑induced copper‑associated hepatopathy and the need to reconsider how much copper is in commercial dog food.

Dr. Hille Fieten (Utrecht University) leads the copper‑associated hepatitis research program within Utrecht’s Expertise Centre for Veterinary Genetics. Her PhD and subsequent work have focused on the diagnosis, treatment, and genetic background of copper‑associated hepatitis in Labrador Retrievers, including how dietary copper and zinc levels, genetic variants, and different stages of disease (normal, subclinical, clinical) interact over time. Fieten’s group has produced some of the strongest evidence we have that subclinical hepatic copper accumulation exists, that it is influenced by diet, and that early, risk‑based nutritional management can change the trajectory of disease in susceptible dogs.

Soul Dog Synergy exists because of my heartdog Sheepdog Riggs, an Old English Sheepdog who lived bravely and successfully with copper‑associated hepatopathy. In the early days, the lack of clear direction, the conflicting information, and some frankly unsafe advice we were given online and made it obvious that there was a gap for owners who needed science‑based, structured guidance instead of guesswork. Out of that experience, my support group was created as a deliberately evidence‑focused space that may feel strict at times, but only because safety, successful management, and clear guidelines for this disease have to come first.

The Facebook group and this site were built to pull peer‑reviewed science, regulatory context, and lived experience into one place. The tier system presented here is my own educational framework, but it is not invented out of thin air—it is a practical way of translating what hepatologists and nutrition researchers already do (separating dogs into average‑risk, increased‑risk/subclinical, and clinically affected) into concrete, WSAVA‑aligned diet choices for real dogs and their people.

Copper basics and why diet matters
Copper supports hemoglobin synthesis, connective tissue integrity, immune competence, and normal neurologic function in dogs (Amundson & Center 2023). Because copper is an essential trace element that cannot be synthesized endogenously, the entire body burden must be supplied through dietary intake.

Key regulatory points

AAFCO sets a minimum copper requirement of 7.3 mg/kg dry matter (DM) for adult maintenance and 12.4 mg/kg DM for growth and reproduction in dogs (AAFCO Expert Panel 2023; Amundson & Center 2023).
AAFCO does not set a maximum for copper in foods intended for normal dogs, whereas FEDIAF uses an upper guideline of 28 mg/kg DM (Amundson & Center 2023; AAFCO Expert Panel 2023).
Understanding the Regulatory Divide

Understanding the Regulatory Divide
AAFCO has declined to set an upper limit because its expert panel concluded there is not enough controlled data in normal dogs to define a truly safe maximum, and that choosing a number without evidence would be arbitrary and potentially misleading. FEDIAF’s 28 mg/kg cap, by contrast, was adopted from an EU environmental regulation designed to limit copper accumulation in soil and water, not from studies defining a toxicity threshold for individual dogs. This regulatory split is discussed in more detail in my article on why AAFCO has no copper upper limit while FEDIAF does.

A survey of common over‑the‑counter (OTC) dog foods found a median copper content of about 4.4 mg/1000 kcal (roughly 11–12 mg/kg DM, depending on energy density), about 2.4 times the AAFCO minimum, with some products around 9 mg/1000 kcal (approximately 5 times the minimum. Nutritional reviews and expert commentary, including from Dr. Center, have raised concern that sustained feeding of highly bioavailable copper at these levels may be contributing to the growing burden of CuAH (Center; Amundson & Center 2023; MSU presentation; AVMA 2022 copper article).

What Fieten’s work tells us about “risk”
Much of the best evidence about subclinical copper accumulation versus overt disease comes from work in Labrador Retrievers by Fieten and colleagues.

Key findings include:

Many Labradors from affected families have increased hepatic copper on biopsy while still clinically normal—this is termed subclinical hepatic copper accumulation (Fieten et al. 2015; Fieten, “Dietary management of Labrador Retrievers with subclinical hepatic copper accumulation”).
Feeding a low‑copper, higher‑zinc diet to clinically normal Labradors with increased hepatic copper reduced hepatic copper concentrations in a substantial subset of dogs over time (Fieten et al. 2015; Fieten et al. J Vet Intern Med 2015).
In inherited copper‑associated hepatitis, long‑term management with low‑copper, high‑zinc diets can reduce reliance on continuous chelation therapy in many dogs (Fieten et al. 2014, Nutritional Management of Inherited Copper‑Associated Hepatitis).

These studies separate dogs not only into “has disease / does not have disease,” but more precisely into genetically susceptible, subclinical hepatic copper accumulation, and clinically affected CuAH. That structure is the foundation for the “tiers” used below (Fieten 2015; Fieten 2020).

What Center and recent reviews add
Dr. Center and other hepatology experts have emphasized that CuAH is now recognized in many breeds and mixes, not just the classic copper‑associated breeds. Chronic exposure to high, highly bioavailable dietary copper appears to be a major driver when combined with genetic susceptibility (Center; Purina Institute CuAH overview; Amundson & Center 2023; MSU presentation).

From these sources, several points are clear:

Nutritional therapy is central to treating confirmed CuAH: strict copper restriction (often around or below 1.25 mg/1000 kcal) plus chelation in dogs with high hepatic copper burdens, followed by long‑term maintenance on copper‑restricted diets (ACVIM consensus 2019; Lidbury 2023 case report; Center; Purina Institute).

Dogs with subclinical hepatic copper accumulation (elevated liver copper without clinical signs) can often be managed with less drastic copper restriction, especially if interventions start early (Fieten et al. 2015; Fieten et al. 2014).
Because CuAH is increasingly seen across breeds, attention to copper intake is reasonable even for dogs outside the classic predisposed list, especially when genetic variants or family history are present (AVMA 2022; Amundson & Center 2023; Purina Institute).

A risk‑based (tiered) framework
The scientific literature does not use ‘Tier 0, 1, 2’ labels; those tiers are my own educational overlay. The underlying stratification, however, comes directly from how studies and consensus statements already group dogs into:

Dogs without identified risk.
Dogs that are genetically or familially at risk and/or have subclinical hepatic copper accumulation.
Dogs with clinical CuAH (abnormal liver enzymes plus biopsy‑confirmed high hepatic copper).

The tier labels below are simply a practical way of organizing these existing categories into a framework owners and primary‑care veterinarians can use in day‑to‑day diet decisions (Fieten 2015; Fieten 2020; ACVIM consensus 2019).”

Tier 0 – Average‑risk dogs
Profile

No breed known for copper‑associated hepatopathy.
No family history of CuAH.
No CAH‑associated genetic variant identified (e.g., ATP7B) on DNA testing.
Normal liver enzymes on routine monitoring and no clinical signs of liver disease (Lidbury; Center).

Diet goals

Feed a WSAVA‑style, complete and balanced diet from a company with strong nutritional expertise and quality control (Cornell Riney Canine Health Center; Purina Institute).
Avoid unnecessarily high copper levels and extreme formulations (e.g., very organ‑heavy diets with large amounts of ruminant liver), especially when there are lower‑copper, equally complete alternatives (Center; Amundson & Center 2023).

Reasonable copper range
A practical target for average‑risk dogs is to stay roughly within about 7–20 mg/kg DM, which corresponds to about 1.8–4 mg/1000 kcal for typical energy densities (AAFCO Expert Panel 2023; Center; Amundson & Center 2023).
This range meets or modestly exceeds AAFCO minima without drifting into the very high copper territory seen in some contemporary diets (Center; AAFCO Expert Panel 2023).

Rationale
The OTC survey showing median copper around 4.4 mg/1000 kcal, with some diets around 9 mg/1000 kcal, supports the idea that many modern diets cluster around 2–5× the minimum. Given the lack of a defined safe upper limit and rising CuAH prevalence, it is reasonable to avoid the high end when equally sound lower‑copper options exist, even in dogs without known risk (Center; Amundson & Center 2023; AAFCO Expert Panel 2023).

Tier 1 – Increased risk or subclinical changes
Profile (any of the following):

Dog from a breed with known copper predisposition (e.g., Labrador Retriever, Bedlington Terrier, Doberman Pinscher, Dalmatian, West Highland White Terrier, some Spaniels), or closely related to affected dogs (Lidbury; Vetlexicon; Purina Institute).
Dog carrying one or more CAH‑associated genetic variants (e.g., ATP7B accumulating variant, lack of protective ATP7A/RETN variants) on DNA testing (Embark copper toxicosis test; UC Davis VGL; Fieten 2020).
Dog with increased hepatic copper on biopsy but no overt clinical signs (subclinical hepatic copper accumulation), as in the Fieten Labrador cohorts (Fieten et al. 2015).
Dog with mild but persistent liver enzyme changes where CuAH is a differential diagnosis (Lidbury; Frontiers 2023 case report).

Diet goals

Proactively keep dietary copper close to the minimum required for health while maintaining WSAVA‑quality nutrition (Purina Institute; Fieten 2015; Fieten 2014).
Emphasize diets lower in copper and with adequate or relatively higher zinc, echoing the low‑copper, higher‑zinc strategies that reduced hepatic copper in some Labradors with subclinical accumulation (Fieten et al. 2015; Fieten 2014).

Suggested copper range
A practical band for many at‑risk or subclinical dogs is about 7–15 mg/kg DM (roughly 1.8–3 mg/1000 kcal), based on the concept of staying close to minima while still providing complete and balanced nutrition (Fieten 2015; AAFCO Expert Panel 2023; Center).

Rationale
Fieten’s studies demonstrated that low‑copper, higher‑zinc diets can reduce hepatic copper in a subset of clinically normal Labradors with subclinical hepatic copper accumulation (Fieten 2014; Fieten 2015).

Practical points

Work with veterinarians to monitor ALT and other liver values periodically (e.g., annually, or more often if abnormalities are present) (Purina Institute; Frontiers 2023).
Request typical analysis from the food manufacturer to confirm copper content and, ideally, zinc content (AAFCO Expert Panel 2023; Center).
Maintain lean body condition; overfeeding increases total copper intake in direct proportion to excess calories (Amundson & Center 2023; Center).

Tier 2 – Clinically affected CuAH
Profile

Persistently elevated liver enzymes (especially ALT) plus compatible imaging, and
Liver biopsy confirming increased hepatic copper beyond accepted thresholds (often >400–600 µg/g dry weight), with histologic evidence of hepatitis (ACVIM consensus 2019; Lidbury; Center).

Diet goals

Therapeutic copper restriction as part of a comprehensive treatment plan (diet + chelation ± zinc), then long‑term maintenance on moderately restricted diets once copper is reduced (Frontiers 2023 case; Purina Institute; Center).

Typical copper target
Many therapeutic hepatic diets and case reports target dietary copper at or below about 1.25 mg/1000 kcal (sometimes around 1.2 mg/1000 kcal), combined with adequate zinc and adjusted protein (Fieten 2014; Frontiers 2023; Center).

Evidence
Nutritional management reviews and case series support strict copper restriction plus chelation during the debulking phase, followed by maintenance on lower‑copper diets to prevent re‑accumulation (Purina Institute; Frontiers 2023; Center; Fieten 2014). Long‑term outcomes are improved when dietary control is implemented early and maintained consistently (Lidbury; Frontiers 2023; Fieten 2014).

WSAVA‑aligned diet selection across all tiers
Regardless of tier, diet selection should remain within WSAVA‑aligned principles:

Choose companies that employ qualified veterinary nutritionists and have robust quality control (Cornell Riney CHC; Purina Institute).
Prefer diets that have undergone feeding trials when possible, or are at least formulated to AAFCO/FEDIAF with clear nutrient data (AAFCO Expert Panel 2023; Purina Institute).
Ask manufacturers for typical copper (and zinc) values.

Learn more about how to choose a WSAVA‑aligned diet, what questions to ask manufacturers, and why this framework matters for long‑term liver health in my separate guide on selecting dog food.

The risk‑based copper bands discussed here are meant to guide selection among such diets, not to push owners toward unbalanced home recipes or non‑validated formulations.

What the WSAVA copper numbers I’ve collected tell us
When I contacted several WSAVA‑aligned manufacturers about their large‑breed formulas for Baby Gentry, in preparation for my new Old English Sheepdog puppy, the copper numbers they provided were remarkably consistent. Across Eukanuba, Royal Canin, Hill’s, and Purina Pro Plan, the large‑breed puppy and large breed adult diets I asked about clustered between roughly 3.3 and 4.1 mg copper per 1000 kcal, (with the Labrador‑specific Royal Canin formulas for my members slightly lower at around 2.6–3.0 mg/1000 kcal as anticipated.)

Practically, this means:

These WSAVA large‑breed diets sit in a moderate copper range that is close to the lower end of typical OTC products but well above therapeutic hepatic diets, as expected.
Internal consistency is good both within and between brands, so rotating among these formulas is unlikely to create big swings in copper exposure on a per‑calorie basis, aside from the modest additional margin offered by the Labrador‑targeted SKUs.
Looking at copper per 1000 kcal (rather than only ppm) matters because dogs eat calories, not percentages on a label. A 4 mg/1000 kcal diet fed at maintenance will deliver a similar daily copper load whether it comes from Eukanuba, Royal Canin, or Pro Plan, which is exactly the kind of predictability we want when managing risk rather than treating active disease.

For Tier 0 and Tier 1 dogs, these “WSAVA” large‑breed options are solid examples of diets that stay near the lower, evidence‑supported end of copper intake without dropping into therapeutic restriction. From a copper‑load standpoint, they can largely be treated as interchangeable, with the Labrador formulas offering a small but real extra buffer for owners who want to be more conservative – if this fits their dog’s needs.

This kind of internal consistency in copper per 1000 kcal across formulas and brands is exactly why ‘WSAVA‑style’ companies are prioritized: they have veterinary nutritionists on staff, tight quality control, and routinely analyzed nutrient data, so mineral levels like copper are much more predictable from bag to bag than in many non‑WSAVA brands.

How owners can apply this framework
In practical terms, an owner and veterinarian can use this structure as follows:
1. Identify the likely tier
Review breed, family history, DNA results (if available), current liver enzymes, and any biopsy findings. Classify the dog as average‑risk (Tier 0), increased or subclinical risk (Tier 1), or clinically affected CuAH (Tier 2).
2. Match diet copper to tier
Within WSAVA‑style diets, ask manufacturers for copper content and choose products whose copper levels fall within the suggested range for the dog’s tier. Ensure the diet remains complete and balanced and does not compromise other nutrients in the process of restricting copper (Amundson & Center 2023).
3. Monitor and adjust
Recheck liver enzymes periodically; if ALT or other markers rise, re‑evaluate tier and consider additional diagnostics (e.g., ultrasound, biopsy). If biopsy reveals significant copper accumulation, move from a Tier 1 strategy to a Tier 2 therapeutic approach under specialist guidance (ACVIM consensus 2019; Frontiers 2023).
4. Maintain healthy body condition
Because copper intake scales with calories, avoiding overweight status is a simple but important part of copper management in all tiers (Amundson & Center 2023; Center).

Why this matters even “without disease”
Fieten’s work in Labradors demonstrates that subclinical hepatic copper accumulation exists and can be modified by diet in genetically susceptible dogs before overt clinical disease develops. Consensus guidance and recent reviews emphasize that rising copper levels in commercial diets may be contributing to the increasing burden of CuAH across breeds (MSU presentation; Amundson & Center 2023; Fieten 2015; Fieten 2014; Center).

Using a tiered, risk‑based approach allows owners and veterinarians to:

Avoid unnecessary extremes in dogs with no identified risk.
Take proactive, moderate steps in dogs with genetic or familial risk or early subclinical changes.
Implement appropriate, evidence‑supported therapeutic restriction in dogs with confirmed CuAH.

All of this can be done while staying firmly within WSAVA‑aligned, evidence‑based nutrition, rather than relying on fear, guesswork, or unbalanced diets.

References & Further Reading