8 min read

Grain-Free Diets for Dogs: Yes or No?


By Wag! Staff

Published: 02/12/2021, edited: 03/19/2024

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From raw meat to organic treats, there have been many different emerging dog diets over the years. Since the mid-2000s, grain-free dog food has been an increasingly popular alternative dog diet. Many mainstream dog food companies now offer grain free dog food recipes for pups to enjoy. 

But, is a grain-free diet for dogs recommended? Spend some time researching the topic and you'll find a lot of negative, as well as positive, reviews of grain-free dog foods. So what are grain-free dog foods? Are they suitable for your dog, or are grain free diets bad for dogs? What do vets think about feeding dogs a grain-free diet? And, what are the benefits of a grain free diet for dogs?

Before you make any decisions, read our deep dive into grain-free dog food to see if you should feed them to your dog.

In this guide, you’ll learn:

Should I feed my dog a grain-free diet? Key takeaways

  • There are pros and cons to a grain-free diet, with no definitive answer as to whether a grain-free diet is better or worse for dogs.
  • The main pros of a grain-free diet are it's beneficial to dogs with grain allergies or sensitivities, is higher in protein, and aids digestion. 
  • Grain-free diets with high levels of peas, lentils, legumes, and potatoes are linked to dilated cardiomyopathy (DCM). 
  • Grain-free dog foods tend to be more expensive and contain high carb levels.
  • Grain-free dog food is nutritionally balanced for dogs as long as it meets the guidelines established in the AAFCO nutrient profiles. 
  • Dr. Linda Simon, MRCVS MVB, says grain-free dog foods are fine for most dogs, but there is evidence that grain-free diets could cause heart disease.
  • Consult your vet if you plan on switching your dog to a grain-free diet.

What is grain-free dog food?

Quite simply, a grain-free diet means the dog food contains no grains.

Grains commonly used in dog food include:

Dog food brands commonly use grains in dog foods, especially kibble. To compensate for the lack of carbohydrates, grain-free dog food usually contains a different carb source, like lentils, peas, and potatoes.

Most grain-free dog foods have a similar amount of carbs to grain-inclusive dog food.

What are grains in dog food?

According to the Grains & Legumes Nutrition Council, grains are: ‘The edible seeds of specific grasses belonging to the Poaceae (also known as Gramineae) family.’ Grains are typically ground for use in breads and cereals and are also a common ingredient in dog food. Grains are high in fiber and generally recognized as good for the digestive system since they aid in the passage of stool and feed healthy gut bacteria.

Some dogs might develop an allergy to grains or a food allergy related to grains, which may require a change in diet. We’ll cover this in the ‘benefits of a grain-free diet’ section below.

Should dogs have grains in their diet?

Dogs have evolved to be able to digest grains — as omnivores, they can eat plant matter as well as meat.

While dogs don’t need grains to get the glucose they need to survive, they need at least some form of glucose in their diet. Starchy vegetables and legumes provide this glucose in grain-free foods, whereas wheat, rice, and other grains provide this glucose in grain foods. Grains offer dogs both fiber and prebiotics to keep their digestive system running smoothly. 

Obviously, you shouldn’t feed your grain-allergic dog food containing grains, but remember, only a licensed veterinarian can diagnose this condition. We don’t recommend switching a healthy dog to a grain-free diet without first consulting with a veterinarian.

various grains on a table - Grain-Free Diets for Dogs

Benefits of a grain-free diet for dogs

So why feed your pup a grain-free diet? Here are a few benefits of a grain free diet for dogs. 

Grain free dog food can reduce allergies and sensitivities

Food allergies and sensitivities are one of the main reasons people feed their dogs a grain-free diet. However, grain allergies aren't the most common food allergies in dogs. 

A 2016 study of 297 dogs with allergens found that wheat was the fourth most common food allergy behind beef, dairy products, and chicken. Of the dogs studied, 13% had wheat allergies, and 6% had soy allergies. Overall, less than 1% of dogs have a grain allergy.

If your vet thinks your dog has a food allergy, they might suggest a 'food trial,' which involves feeding your dog a limited-ingredient diet. Through the process of elimination, a food trial will reveal if your dog has any allergies. Your vet may suggest grain-free or gluten-free dog food if they suspect a grain allergy.

Grain free dog food may improve skin and coat health

Grain-free dog foods are generally higher in animal-based protein than grain-inclusive dog foods, so they may be better for the condition of your dog's skin and coat. Animal protein contains all of a dog's essential amino acids, some of which help a dog's fur stay healthy and shiny. 

A grain-free diet replicates an ancestral diet

An increased emphasis on feeding dogs an ‘ancestral diet’ is another reason grain-free dog foods are popular. An ancestral diet is based on the idea that dogs should eat the same diet as the wolves they're descended from. 

Ancestral diets involve feeding dogs raw or high-protein foods with limited ingredients and a low percentage of fruit and vegetables. Ancestral diets often contain no grains. 

Ancestral diets aim to improve digestion and promote healthy muscles and joints. They're also meant to be tastier for dogs due to their high meat content. This is due to their limited ingredients and high protein levels. 

But it's worth noting that dogs are omnivores, unlike their carnivorous ancestors. Dogs have evolved to digest fruits, vegetables, and grains the same as animal-based protein. 

Grain-free dog food has less starch

Grains are a primary source of starch in dog foods. While a small amount of starch is perfectly healthy for dogs as it provides energy, high proportions can lead to obesity and digestive issues.

Potential risks and drawbacks of a grain-free diet for dogs

We've looked at the benefits, but what about the potential risks of a grain-free diet?
Let’s take a look at some of the drawbacks and risks of feeding your dog a grain-free diet. 

Grain free dog food has links to Dilated cardiomyopathy (DCM)

The biggest, and most serious, risk of feeding your dog a grain-free diet are its links to non-hereditary dilated cardiomyopathy (DCM). In 2019, the U.S. Food and Drugs Administration (FDA) opened an investigation into grain-free dog foods. The investigation is specifically interested in grain-free dog foods that contain high levels of peas, lentils, pulses, and potatoes. 

The FDA study between 2014 and 2019 found that of 515 reports of DCM, 90% of dogs were on a grain-free diet. Additionally, 93% of dogs were on a diet containing peas and/or lentils. 

The FDA has no new meaningful data to share concerning their investigation as of December 2022. Therefore, there's no conclusive evidence that grain-free dog foods cause DCM. Consult with your vet if you're concerned about links between grain-free dog food and DCM. 

Grain free dog food is high in carbohydrates

One myth about grain-free dog foods is that it's lower in carbs than grain-inclusive dog foods. That’s not entirely accurate. Many grain-free dog foods contain high-carb grain alternatives, like potatoes and peas. So, grain-free dog food might not be the best option if you're trying to manage your dog's weight and it may cause them to pile on the pounds

It’s typically pricier than grain-inclusive dog food

Grain-free dog foods are generally more expensive than grain-inclusive dog foods because of their higher meat content and inclusion of pricier produce. In comparison, grains are inexpensive and often used as ‘filler’ ingredients, which then help to drive down the price of your dog's dinner.

Do vets recommend grain-free dog food?

After reading the pros and cons of grain-free dog foods, you're probably wondering if veterinarians recommend them. One of Wag!'s veterinary consultants, Dr. Linda Simon MRCVS MVB, had this to say about grain-free dog foods:

"For most dogs, [grain-free] diets are just fine,” she says. “They have real benefits for those with grain sensitivities, though this isn't a very common food allergy.

For some dogs, however, grain-free diets could be damaging. There's some evidence of an increased risk of heart disease in a subsection of the population fed grain-free diets. Researchers are looking into why this is and theorize it may be the increased legume consumption."

Veterinarians agree that grain-free dog foods are generally safe for dogs, but foods containing large amounts of legumes, lentils, and pulses could increase the risk of heart disease.

Is grain-free dog food suitable for all dogs?

As mentioned, grain-free dog foods suit most dogs, but not all dogs. Dogs with grain allergies or sensitivities will benefit most from grain-free diets. 

But can you feed a grain-free diet to a dog if they don't have a grain allergy? Yes, grain-free dog food recipes are safe to feed to dogs without grain allergies. Grain-free dog foods will fulfill all their nutritional needs as long as they meet the guidelines established in the Association of American Feed Control Officials (AAFCO) nutrient profiles

Grain-free diets can be beneficial to dogs with digestive issues. Less starch and more protein and fat means grain-free diets are easier to digest. Your vet may recommend a grain-free or limited-ingredient dog food if your dog is having digestive issues. 

However, it's also a myth that grains are bad for dogs and shouldn't be a part of their diets. Grains are a good source of antioxidants, carbohydrates, and fat. These properties help support a dog's coat health, immune system, heart, and more. Plus, grains contain glucose, which is a minor energy source for dogs which helps maintain normal blood sugar levels.

cloth bags full of different grains

Thinking about switching your dog to a grain-free diet? We’ve recommended a series of some of the best and most popular grain-free dog food brands, as well as companies that sell grain-free recipes, for you to consider: 

Tips for transitioning your dog to a grain-free diet

Transitioning your dog from grain-inclusive to grain-free food — or vice versa — should be gradual to avoid upsetting your dog's stomach. Here are some tips for transitioning your dog onto a grain-free diet. 

Consult your vet before making the switch to grain free dog food

Chat with your vet if you're considering changing your pup's diet to a grain-free recipe. Your vet can recommend the best grain-free dog food based on your dog's age, breed, and health. They'll also be able to tell you if the food you're considering is the best option for your dog. 

Transition your dog gradually to their new diet

You should transition your dog to their new grain-free diet over a seven-day period. Gradually replace their old food with their new food every two or three days. Start by adding 25% new food to their old diet, then 50%, and finally 75% before making a complete switch to a grain free dog diet. 

Depending on their digestive health, you may want to take slightly longer to change your dog's diet. Most dog food brands have guidelines on their websites for transitioning your dog to their food, which you'll want to follow. Consult your vet if you're unsure how to switch your dog's diet. 

Watch for signs your dog's new grain-free diet is having a positive or negative effect

Your dog may experience some digestive issues, like diarrhea, constipation, and vomiting, as you transition them to a new diet. Minor digestive issues during a transition are relatively normal, especially if your dog has an easily upset stomach. 

You may want to slow the transition process if your dog's poop is runny or softer than usual. Consult your vet if digestive issues persist after changing your dog's diet. They may have a sensitivity or allergy to an ingredient, meaning you'll want to change their diet again. 

You should keep watch for positive changes in your dog. More energy, better coat health, and healthier digestion are clearly visible signs that your dog's new diet is beneficial.

Wondering if a grain-free diet would benefit your dog? Chat with a veterinary professional 24/7 with Wag! Vet Chat!

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