Grain-Free Dog Food: What It Means, the Heart Question and Whether Your Dog Needs It

Grain-free dog food leaves out cereal grains such as corn, wheat, rice, oats, barley and sorghum. To replace them, these foods usually use peas, lentils, chickpeas, beans, potatoes, sweet potatoes, tapioca or other starches. Those ingredients can supply starch, fiber, protein and other nutrients, so the food still has carbohydrates. As the FDA's questions and answers page frames it, the issue is which ingredients stand in for the grains, not whether carbs are present.

"Grain-free" is a formulation choice. It is not a promise of better nutrition. The label details that tell you more are the nutritional adequacy statement and how the food is named.

The AAFCO naming rules explain why a product name can mislead you. Under the AAFCO label guide, a name like "Beef Dog Food" means the named ingredient makes up at least 95% of the product by weight, not counting added water. A name with "dinner," "entrée" or "platter" follows the 25% rule instead.

These rules only describe how much of a named ingredient is in the product. They do not tell you the food is nutritionally complete or right for your dog.

The nutritional adequacy statement does that job. It tells you whether the food is complete and balanced, which species and life stage it is made for, whether that claim rests on nutrient formulation or feeding trials, and whether it is meant only for occasional or supplemental feeding. The ingredient list is ordered by weight, but it does not show how much of each ingredient is in the bag, and it does not prove ingredient quality.

In July 2018, the FDA announced an investigation into reports of canine DCM in dogs eating certain diets. DCM is a heart condition in which the heart muscle weakens and the heart gets larger. Many of the reported foods were labeled grain-free and had peas, lentils, other pulses or potatoes high on the ingredient list.

The FDA's December 23, 2022 update made these points:

• The FDA had received reports involving non-hereditary DCM.
• The reports involved both grain-free and grain-containing diets.
• Most of the diets in reports had non-soy legumes or pulses high in the ingredient list.
• Pulses are not inherently dangerous and have been used in pet foods for many years.
• The FDA could not investigate or verify every report.
• The number of reports alone does not establish causation.
• The FDA did not plan more public updates until meaningful new scientific information became available.

So, what has not been proven? The FDA has not shown that grain-free food alone causes DCM, has not named one responsible ingredient, and has not declared every grain-free diet unsafe. The picture involves formulation, how well nutrients are absorbed, processing, ingredient sourcing, how long a dog ate the diet, breed and other possible factors. Some affected dogs had low taurine, but many had normal taurine levels, so taurine does not explain every case.

Because FDA public updates can change, check the FDA page for anything newer than December 2022 before you make a big decision.

Veterinary nutrition groups such as WSAVA focus on complete nutrition, an individual look at each dog, and whether the maker has real formulation skill and quality control. They do not focus on marketing categories like grain-free.

The AAHA 2021 nutrition guidelines say that, given the evidence available, the most conservative approach is to avoid grain-free diets or diets high in legumes, and they describe the issue as still developing.

Vets tend to be cautious for a few reasons:

• The FDA reports involved many diets that were both grain-free and pulse-heavy.
• Most dogs do not need grain-free food.
• Food allergies in dogs more often involve animal proteins than grains.
• Leaving out grains does not show better digestibility or better nutrition.
• Some grain-free foods swap grains for several pulse ingredients.

A vet may still suggest a grain-free or other restricted diet for a particular dog with a documented nutritional need or ingredient restriction. That call rests on your dog's medical history, not on a general belief that grains are harmful.

Does that mean grain-free food is linked to heart disease in every dog? No. The FDA has not established that every dog eating grain-free food will develop heart disease. It does mean that a heart-health worry is a fair reason to talk to your vet about your dog's food.

If your dog collapses, faints or has severe trouble breathing, treat it as an emergency and get to a vet right away. Use the emergency vet directory to find one near you.

AAHA lists these warning signs of heart disease:

• A new heart murmur
• An irregular heartbeat, called an arrhythmia
• Exercise intolerance, such as tiring on walks that used to be easy

A new murmur, an arrhythmia or tiring easily calls for a vet visit soon, even if your dog seems fine otherwise. Your vet is the one who can tell you whether heart tests are needed. A dog with these signs needs veterinary care, not a home diet experiment. If you need a regular vet, the veterinarian directory can help.

Not by default. True food allergy is uncommon. The Merck Veterinary Manual reports food allergy in about 1% to 2% of dogs seen by vets. Among dogs with skin disease the reported range is 0% to 24%, and among dogs with itching it is 9% to 40%. Those wide ranges reflect differences between studies.

Merck lists beef, dairy products, chicken, wheat and lamb as the common canine food allergens. Soy, corn, egg, pork, fish and rice are reported less often. A dog can react to any dietary protein, so a grain-free bag can still contain the thing your dog reacts to.

Grain-free food is not a general fix for itching for a few more reasons. Most itchy dogs do not have a grain allergy. Environmental allergies, parasites and infections cause itching too. Blood, saliva and skin tests are unreliable for diagnosing food allergy, and the dependable method is a strict, vet-directed elimination diet followed by a rechallenge.

I won't repeat the whole elimination-trial process here. It is laid out step by step in our guide to dog food allergies and how vets confirm them, and the broader guide to dog allergies and constant scratching covers the other causes. If your dog keeps scratching, see your vet instead of switching bags again and again.

Properly processed grains can be digestible and nutritious. Tufts' Petfoodology makes that case for corn, and cooked and ground grains can be highly digestible. Calling grains "cheap filler" is a claim you cannot make across the board.

If you want to know whether a particular grain is safe as a food or a snack, we have short entries on rice, corn and oatmeal, each with its own cautions.

The label and the company tell you more than the "grain-free" tag. WSAVA's food selection toolkit suggests asking:

• Who formulates the diet, and what are their qualifications?
• Does the company employ an experienced pet food formulator?
• Is the food complete for my dog's life stage?
• Is that based on nutrient formulation, feeding trials or both?
• What quality-control steps are used for ingredients and finished products?
• Does the company do or publish nutrition research?
• Can the company give calorie information and nutrient details?

WSAVA says quality control should include checking ingredients, analyzing the final diet for nutrients, and toxicology, bacteriology and packaging or shelf-life checks. It also warns that ingredient lists do not show ingredient quality and can be misleading about overall food quality. Calling or emailing the manufacturer with these questions is a normal thing to do.

Nothing shows that a higher-priced grain-free food is better nutrition just because it leaves out grains. A lower-priced food that is complete and balanced may meet your dog's needs well, while a pricier one may not suit an individual dog.

If money is tight, compare these things:

• The complete-and-balanced statement
• The right life stage on the statement
• Calories per cup, can or gram
• The daily feeding amount on the label
• Who formulates the food and what quality control they use
• Whether the food is a complete diet or only supplemental
• Whether your dog keeps a healthy weight, appetite and normal stools on it

Cost per day tells you more than the price of the bag. Divide the bag price by the number of days it lasts at the feeding amount on the label. Homemade diets do not usually save money either, according to the Merck Veterinary Manual.

Change foods gradually, following the manufacturer's directions and your vet's advice. While you switch, watch appetite, stool quality, vomiting, weight and general condition. If something goes wrong, our guides on dog vomiting and dog diarrhea explain what to watch for and when to call.

Talk to your vet before you change food if your dog has a diagnosed disease, repeated digestive problems, a suspected allergy or any heart concern. Senior dogs have their own needs too, and our guide to senior dog care covers the changes that come with age.

A board-certified veterinary nutritionist is worth asking about when your dog has a medical condition that affects what they can eat, or when you are thinking about a restricted or homemade diet. Your vet can refer you.

Here is a short checklist to carry to the store or the vet:

• Read the nutritional adequacy statement.
• Confirm the food matches your dog's life stage.
• Check whether it is complete or supplemental.
• Ask who formulates it and what quality-control testing is done.
• Check calories and the daily feeding amount.
• Write down every treat, supplement and bit of table food if you suspect an allergy.
• Ask your vet about persistent itching, vomiting, diarrhea or weight change.
• Get urgent care for collapse, fainting or severe breathing trouble.

Short answers to the questions owners ask most about grain-free food.

Not automatically. Check complete-and-balanced status, who formulated the food, how quality control works and whether it suits your individual dog. Leaving out grains does not make a food better.

When a product name has a named ingredient with no extras, like "Chicken Dog Food," that ingredient must make up at least 95% of the product by weight, not counting added water, per AAFCO. Counting water, the minimum is 70%. It describes the name, not the food's overall nutrition.

Itchy skin and digestive upset are common signs of a food reaction, but they have many other causes, and grains are not the usual trigger. Beef, dairy, chicken, wheat and lamb are more common allergens. See your vet for a proper work-up instead of guessing.

Ask your vet about your dog's diet, especially if your dog has heart signs, a diagnosed heart condition or other medical needs. If your dog is healthy, you can plan a gradual change to a complete and balanced food rather than switching overnight.

Look at your dog's food label today and find the nutritional adequacy statement. If it says the food is complete and balanced for your dog's life stage, you are not in a rush. If you see heart signs, a new murmur, fainting or breathing trouble, or if the itching never settles, call your vet. For help finding one, use our veterinarian directory. I can't tell you what is right for your dog, but a vet who knows your dog can.

• aafco.org: AAFCO label guide
• American Animal Hospital Association: AAHA 2021 nutrition guidelines
• Merck Veterinary Manual: Merck Veterinary Manual
• Merck Veterinary Manual: Merck Veterinary Manual
• sites.tufts.edu: Tufts' Petfoodology
• U.S. Food and Drug Administration: FDA investigated reports
• U.S. Food and Drug Administration: FDA's questions and answers page
• wsava.org: WSAVA
• wsava.org: WSAVA