Vet Reviewed

By The Farmer's Dog | May 9, 2024

Co-authored by Rae Sires DVM, DACVIM (Nutrition), and Joseph Wakshlag DVM, PhD, DACVIM (Nutrition).

Key Takeaways

  • Copper is an essential nutrient in your dog’s diet, ​​necessary for a range of bodily functions. As with any nutrient, balance is key; too much can be toxic to dogs and is associated with liver disease.
  • Copper in dog food has been the subject of much media and scientific attention in recent years. A 2021 American Veterinary Medical Association (AVMA) Journal research paper cited a perceived increase in copper-associated liver disease in dogs and recommended that AAFCO reestablish an upper limit for copper in its nutrient profiles. 
  • The Farmer’s Dog food is formulated by on-staff, board-certified nutritionists (including one of the authors of the AVMA paper) to be complete and balanced and healthy to feed for the life of your dog. 
  • Recipes include bioavailable copper amino acid chelate, in accordance with industry guidelines and the expertise of our scientists. Our food is made in human-food facilities. Each batch is tested to ensure appropriate nutrient balance and eliminate the risk of over-inclusion.
  • Nothing matters more to us than your dog’s health. Our team of veterinary professionals is at the forefront of nutrition science and continues to lead the way on pet-food health and safety. 


Reports about excessive copper in dog food, and its association with liver disease, have been quietly raising concern among dog owners and veterinarians for the past several years. 

We want to provide reliable, science-backed information about this issue to help you make the best decisions about your dog’s care. To that end, this article was co-written and reviewed by our on-staff, board-certified nutritionists—the same veterinary nutrition experts who develop our recipes. 

Read on for the latest information on copper in dog food, how we safeguard the health of dogs eating our recipes, and advice for keeping your dog safe and thriving.  

What role does copper play in a dog’s diet? 

Copper is an essential mineral, meaning that dogs can’t produce it in their bodies; it needs to come from their diet. It’s key to many facets of your dog’s health, playing an important role in energy production at the cellular level; iron absorption; production of connective tissues, blood vessels, and red blood cells; nervous and immune-system function; and brain development. 

Copper occurs naturally in small amounts in many foods, including organ meats like liver; dark, leafy greens; nuts; mushrooms; shellfish; and whole grains. Because the amount of copper in foods can vary widely depending on sourcing of the ingredient, growing conditions, and many other factors, supplemental copper is also added to most pet-food recipes on the market to ensure they’re complete and balanced, and that each bite of food is meeting a dog’s nutritional needs.  

As with any nutrient, it’s crucial that your dog’s food contains the right amount, and proportion, of copper. Too little copper can cause serious musculoskeletal and other ailments; too much can be toxic, and can negatively impact absorption of other essential nutrients in the diet.

Copper and liver disease in dogs

If you’re reading this article, you may have heard about a reported rise in copper-associated hepatopathy (CAH) in dogs. 

CAH occurs when the liver gradually accumulates more copper than it needs for day-to-day function, eventually resulting in liver disease. This overaccumulation of copper in the liver can lead to chronic hepatitis (inflammation of the liver) and eventual liver failure in extreme cases. 

What makes CAH especially dangerous is that it can go undetected until the late stages of the disease. Signs of CAH can be non-specific and may include lethargy, abdominal swelling, diarrhea, vomiting, weight loss, and jaundice (a yellowing of the skin, gums, and other tissues that can be a sign of a liver ailment). While CAH is rare, and any of these signs can be associated with a wide range of conditions, speak to your vet if you’re concerned about any new or sudden digestive upset or other physical changes.

What causes CAH?

The two main factors associated with the development of CAH in dogs are genetics and diet. 

Breed predisposition 

Certain breeds are considered predisposed to CAH. Research dating back to the 1970s established that Bedlington terriers are prone to copper storage issues—caused by a gene that affects their ability to metabolize copper. Recently, Labrador retrievers were also identified to have a specific gene linking them to CAH. While any breed can theoretically develop CAH, other breeds that seem to be more predisposed than others include Doberman pinschers, Anatolian shepherds, Clumber spaniels, corgis, Dalmatians, Skye terriers, and West Highland white terriers. 

Diet and CAH: Is copper in dog food safe? 

Much of the concern and media coverage around CAH in recent years has centered on the role of dietary copper in the development of the disease.

A 2019 study called “Hepatic copper concentrations in 546 dogs (1982–2015)” noted that CAH was “increasingly recognized” in dogs,” likely due to “observed increases in (hepatic copper concentrations) over time.” In 2021, the American Veterinary Medical Association (AVMA) Journal published a paper called “Is it time to reconsider current guidelines for copper content in commercial dog foods?” The paper’s authors noted: “Over the past 15 to 20 years, we have seen what we believe to be an increased incidence of copper-associated hepatopathy in dogs.” Among the researchers and writers of that paper was Joe Wakshlag, DVM, PhD, DACVIM (Nutrition), who is one of the board-certified nutritionists who develop The Farmer’s Dog food.

AAFCO copper regulations for dog food

The researchers tied the perceived rise of CAH in dogs to changes in the Association of American Feed Control Officials’ (AAFCO) guidelines for copper content in dog food that took place in 1997. They recommended that AAFCO reestablish an upper limit for copper in its nutrient profiles. 

For more context, AAFCO is the body that establishes guidelines for pet food nutritional requirements and labeling and sets minimum and (for some nutrients) maximum amounts of nutrients permitted in dog food. These recommendations are based on available research studies. Due to the extremely limited number of controlled research studies available for dietary copper in both growth of puppies and for healthy adult dogs, AAFCO currently provides a minimum guideline for copper in puppy and adult dog food (3.1 and 1.83 milligrams per 1,000 calories, respectively), but no maximum amount that can be included. Previously, AAFCO had a set maximum value for copper inclusion of 71 milligrams per 1,000 calories of food.  

In 1997, AAFCO amended its recommendations regarding copper in pet food based on a study concerning the extremely low bioavailability of copper oxide (which was commonly used to supplement dog food) as compared to copper sulfate. The organization recommended that pet-food companies use copper sulfate (or chelates), a more bioavailable form of copper, instead of copper oxide in their recipes. 

There are questions as to whether the combination of these two guideline changes—a more bioavailable form of copper and the removal of an upper limit for inclusion—may be contributing to increased copper content in dog foods currently on the market. Those questions will likely remain unanswered, because there are no food samples available that were manufactured prior to 1997. 

Multiple values have been proposed for AAFCO adoption to serve as an interim maximum copper content until a more definitive value can be established. One proposal is to adopt the copper maximum that is currently used by the Fédération Européenne de L’industrie des Aliments Pour Animaux Familiers (FEDIAF), the European Union’s equivalent to AAFCO. However, FEDIAF based its current copper maximum for dog food on environmental concerns, rather than research supporting dog nutritional needs. 

In the wake of the 2021 AVMA article, and after consulting a panel of veterinary nutrition experts over the course of a year, AAFCO elected to maintain its current guidance on copper in dog food. The organization concluded that “there is a lack of definitive evidence linking copper-associated hepatitis in dogs and the copper content in dog foods.”

However, it is important to note that AAFCO is continuing to evaluate options to help guide owners and veterinarians in making more informed decisions regarding copper in dog food. One option AAFCO is considering is creating a “modified copper” or “controlled copper” claim, whereby copper maximums would be indicated in the guaranteed analysis on a pet-food label. At the time of writing, this is an ongoing discussion. 

The FDA continues to review the scientific literature on copper in pet food to determine whether regulatory intervention is warranted. 

What to know about The Farmer’s Dog food formulation and copper

There’s nothing we take more seriously than the health of dogs, and the safety of our food. 

All our recipes are formulated by our on-staff board-certified animal nutritionist and Board-Certified Veterinary Nutritionists® to ensure the food is complete and balanced prior to moving forward with manufacturing and testing.

Our food is made and tested in human-food facilities, according to the same strict safety controls that apply to human food. Each batch of food is evaluated for nutritional compliance to ensure that all ingredients have been added in the right amounts and thoroughly mixed to create a uniform, healthy product. 

Each recipe is a blend of human-grade meat and vegetables. A human-grade vitamin and mineral premix, which includes a source of copper, is also added to our fresh ingredients to ensure a complete and balanced diet. Specific testing is performed on all batches to ensure that our vitamin and mineral premix has been added appropriately to remove the risk of over-inclusion. 

Due to copper being an essential nutrient and required to be a part of a healthy diet for puppies and adult dogs, all of our recipes are supplemented with copper to meet AAFCO guidelines.  Puppies have a higher copper requirement than adult dogs, and it is critical that their bodies have access to a consistent and bioavailable copper source for normal growth and development. 

Our recipes specifically use copper amino acid chelate as a copper source due to its known bioavailability—meaning it is able to be absorbed and used by the dog’s body for essential processes. Other forms of copper, specifically copper oxide, have extremely low bioavailability and may not be appropriate to meet a dog’s dietary copper needs. 

The FDA recently evaluated the copper content in 1,484 over-the-counter canned and dry dog foods, formulated for both adult dogs and all life stages (growth and reproduction). The average copper content of all of our ready-to-eat recipes is below the median value of that study. That is because our recipes are formulated for all life stages and are intentionally made to meet AAFCO guidelines to ensure we meet the nutritional needs of growing puppies and reproducing dogs without excess supplementation.  The Farmer’s Dog recipes are not specifically formulated for the management of liver diseases which require lower than normal copper levels.

Our board-certified nutritionists are industry leaders who regularly participate in AAFCO’s expert panels and closely follow all available releases and updates provided by the FDA and AAFCO, as well as peer-reviewed veterinary journal articles and other industry updates. The Farmer’s Dog also has a team specifically dedicated to food safety, quality, and regulation. Our scientists continually review and assess current literature and scientific support related to all aspects of our food production and formulation. Rest assured, if new guidance for copper inclusion in dog food is released, we will reevaluate and, if needed, reformulate The Farmer’s Dog recipes to continue to ensure the safety and health of all dogs eating our products. 

What if my dog needs a low-copper diet?

If your dog has been diagnosed with CAH or abnormal accumulation of copper in their liver and requires a low-copper diet, they’ll need a specific veterinary therapeutic diet, or a home-cooked diet formulated by a Board-Certified Veterinary Nutritionist ®. At this time, due to the minimum copper concentrations recommended by AAFCO, foods with a lower copper content require direct veterinary oversight when recommending and feeding. Additional management strategies for these dogs include the use of copper chelators, which bind excess copper out of the diet and prevent its absorption, and the addition of antioxidants and liver-protectant supplements into the diet. Your veterinarian will be able to discuss appropriate food options and other specific treatments for CAH in more detail. 

What about feeding treats and copper?

When feeding any complete and balanced food, it is important to avoid giving excessive quantities of treats. 

Treats can add up to excess calories and unintentional weight gain, and giving too many can risk throwing off the nutritional balance of your dog’s diet. For this reason, no more than 10% of your dog’s daily calories should come from treats or unbalanced food items.

Some food items are particularly high in copper, including shellfish and oysters; dark, leafy greens; nuts; and organ meats. Beef liver, for example, is a common ingredient in many training treats. While some of these foods can be healthy if given in moderation and as a portion of your dog’s daily treat allowance, they should be avoided if your dog is predisposed to, or has been diagnosed with, CAH. A full list of foods with high copper content can be found online through the National Institutes of Health website. 

Low-copper foods that could be considered as treat alternatives include apples, bananas, raw carrots, or Greek yogurt (if your dog tolerates it). As always, discuss appropriate copper intake and feeding recommendations for your individual dog with your vet. And, again, feed even healthy treats in moderation.

What you can do to protect your dog’s health

To safeguard the health of your dog’s liver, and their general health, it’s crucial to feed a healthy, complete and balanced diet that meets their specific needs. When choosing a daily diet, it’s important to know how and by whom the food was formulated—look for dog food formulated by board-certified nutritionists according to AAFCO standards. 

As with any question or concern related to your dog’s health, your best course of action is to consult your veterinarian. They’ll be able to evaluate the composition of your dog’s diet, and make the right recommendations.  

Contact us directly 

Complete recipe nutritional profiles, including copper content, are available upon request by contacting our customer support team—available 24/7. 

Veterinary professionals can access complete nutritional profiles at any time through the Vet Team Portal on The Farmer’s Dog site.