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What You Need to Know About Grain-Free Dog Food

Author: Dr. Beth Turner

Published: February 28, 2023

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golden retriever puppy eating food from bowl

What is the primary purpose of food? I think most of us would agree that its main purpose, even though there are others, is to provide the body with the essential nutrients for growth, repair, and maintenance.

Essential nutrients include proteins, fats, carbohydrates, minerals, vitamins, and water. All of which are vital to helping the body function properly.

When the body does not receive an adequate amount of a particular nutrient, it is at an increased risk of developing a disease or illness.

While grain-free diets are very common and some of the most expensive dog food brands on the market, it doesn't mean they are nutritious for your dog. There are many things to consider in assessing whether the grain-free diet you're feeding your dog is beneficial. Many could be harmful. Read on to learn more, and let me know if you have any questions at the end of this article.

Dogs Are Not People

While this may seem obvious, it seems to be forgotten when it comes to feeding our pets. We often want to feed them what we feed ourselves, forgetting their nutritional needs are different.

There are a lot of different diet plans people follow for different reasons. And we assume because those diet plans work for us, they will benefit our dogs. Well, not always.

Back in 2007, there was a gamut of recalls of pet foods produced from products, such as wheat gluten, corn gluten, and rice protein concentrates, that came from China containing melamine (an industrial product). Those foods were recalled because pets were suffering from severe health issues after consuming them.

Additionally, at that time, the trend in human diets was starting to move away from grains and gluten-containing foods.

It was during this time that grain-free and other types of diets increased in popularity, and many pet owners transitioned their dogs to these types of diets since they were marketed as being better for gluten sensitivities, loaded with exotic proteins and legumes, more closely resembled dog’s ancestral diets and overall healthier for dogs.

Just like not all diet trends for people are beneficial, the same applies to our furry friends.

Diets, including boutique, exotic ingredient, and grain free, are referred to as ‘BEG’ diets.

bags of grain that are not used in grain free dog food

Some Grain-Free Truths & Myths

Grain-free diets represent more than 40% of available dry dog food in the United States. In fact, in the USA, from 2012 to 2016, sales increased 221%.

When dog food is labeled as grain-free, it is made without the following ingredients:

  • Wheat
  • Corn
  • Rice
  • Soy
  • Oats
  • Barley
  • Rye

Carb replacements: Since dogs still need carbohydrates for energy, these ingredients are replaced with potatoes (white and sweet) in various forms and/or legumes (peas, beans, lentils, chickpeas, or other legume seed pulses).

Gluten sensitivities: Grain-free diets are often marketed as better for dogs with gluten sensitivities. The fact is that while wheat allergies do exist in dogs, they are uncommon. They equate to about 1 in 10,000 in the whole dog population.

Other sensitivities: Grain-free diets are touted as better for dogs with food hypersensitivities to ingredients such as corn, barley, rice, rye, or oats. But just like wheat allergies, these sensitivities are uncommon.

No 'fillers': There is also the claim that grain-free diets are healthier because ‘fillers’ are removed. Valuable nutrients such as vitamins, minerals, essential fatty acids, and fiber are all provided by whole grains, aka ‘fillers.’ Additionally, protein can be provided by some grain products that are easier for some dogs to digest than the protein obtained from meat.

Low carbohydrates: Low-carb diets were trendy for human weight loss in the late 1990s and early 2000s. The assumption by many pet owners is that grain-free diets are low-carb. The truth is that alternative carbohydrate sources (potatoes, lentils, chickpeas, and peas) are potentially higher in carbohydrates and can result in weight gain. Additionally, these alternatives may provide fewer nutrients and fiber as compared to whole grains but at a higher cost.

The grain-free diets that are lower in carbs can be higher in both fat and calories. This can lead to weight gain, which is less than ideal for dogs with a history of pancreatitis or hyperlipemia (fatty blood).

Dogs are omnivores: Dogs are viewed as carnivores when in fact, they are omnivores. This means they eat (and need) a diet of both meat and plants. This misunderstanding is why many pet owners think grains are hard for their dogs to digest. The good news is that most dogs digest and use the nutrients from those grains very efficiently (more than 90% of dogs).

The alternative sources of carbohydrates are not necessarily better. And they may cause more harm than just tummy issues.

Quality control: Lastly, quality control and nutritional expertise are not the same among all pet food manufacturers. These variations can result in some potential health issues for dogs.

Are Grain-Free (BEG) Diets Healthy or Harmful for Dogs?

There appears to be a connection with all diets under the ‘BEG’ diet classification – boutique, exotic ingredients, and grain free- to diet-associated dilated cardiomyopathy in dogs.

Dilated Cardiomyopathy (DCM)

DCM is characterized by a distention and thinning out of the muscular walls of the heart, causing it to be a less effective pump to move blood throughout the body. As you might imagine, that’s not a good thing! Dogs with DCM are at great risk of progressing to heart failure. You can learn more about the condition in this article from the cardiology department at the Washington State University College of Veterinary Medicine.

To give you a little history, an investigation was begun by the FDA in 2018 after reports of dogs (including breeds without previous known genetic predisposition) developing DCM after consuming diets labeled as grain-free. These diets had as their main ingredients (within the top 10 ingredients listed) peas, lentils, other legume seeds (pulses), and/or potatoes in different forms.

Of the 515 reports of DCM the FDA received between Jan. 1, 2014, to April 30, 2019, the FDA discovered that 90% of those dogs were on grain-free food and 93% were on diets that contained peas and/or lentils. No significant abnormalities were discovered with regard to minerals, metals, and amino acids.

What Is the Cause of Diet-Associated DCM?

Unfortunately, for the vast majority of cases, the cause is unknown. But what has been determined is that the cause is scientifically complex and involves multiple factors.

Research has caused scientists to develop several different hypotheses about what is causing diet-associated DCM; therefore, research is still ongoing.

Some of the links between BEG diets and DCM that have been discovered so far:

Low taurine levels: In some cases, low taurine levels have been noted. One theory is that the legumes interfere with a dog’s ability to absorb taurine from the diet. This hypothesis is not yet proven but continues to be researched. In those cases, improvement occurred with a change in diet and taurine supplementation.

Lower levels of vitamin B: Research findings noted diets associated with DCM had lower volumes of B vitamins. B vitamins are an essential part of the reactions associated with cardiac metabolism.

High concentration of amino acids: Amino acids, amino acids derivatives, and plant-derived compounds, which have been found to contribute to deficiencies in molecules critical to heart function, were found in higher concentrations in DCM-associated diets.

Peas as main ingredient: Reports also indicate that diets containing peas as a main ingredient showed the "greatest association with higher concentrations of compounds in DCM-associated diets.”

mixed breed dog eating from a large white bowl-canva

What to Do If You Feed Your Dog a Grain-Free Diet?

If you feed your dog a grain-free diet, especially if it's a food that contains peas, chickpeas, lentils, or potatoes in place of the grains, I would STRONGLY suggest that you read about the possible link between feeding a BEG diet and the development of Dilated Cardiomyopathy (DCM), a very serious form of heart disease in dogs.

Additionally, read the following articles:

Some Other Things You Should Consider Doing

Veterinary Exam

If you’ve switched your dog to a grain-free diet within the past 6 months and your dog hasn’t had a visit and physical exam with your vet since starting the grain-free diet, it’s a good idea to have your dog checked out so your vet can, amongst other things, listen to your dog’s heart and see if any new murmurs have developed.

A heart murmur is often heard in dogs with DCM. (Note that a heart murmur in a dog can be caused by a variety of factors and conditions, not just DCM.)

If your dog hasn’t had a checkup with your vet within the past 12 months, regardless of how long they've been eating a grain-free diet, it’s a good idea to get one on the schedule so that your vet can do a thorough physical examination of your dog, including listening to their heart for murmurs or other abnormalities.

Learn how to check your dog's heart rate (pulse) and breathing rate (effort). A rapid heart rate and breathing rate, even at rest, are common signs that dogs in heart failure will exhibit. See the video below or ask your veterinarian or one of their nurses to show you. Getting comfortable with these procedures now will help you learn what’s normal for your dog so that you’ll be better able to know if it becomes abnormal later. You can also learn more about the signs of heart failure in dogs in this article from the cardiology department at Tufts University School of Veterinary Medicine.


Taurine Level Check

Consider having your dog’s blood taurine levels checked at your vet’s office. Taurine is an amino acid that is particularly important for the proper health and function of your dog’s heart (as well as their eyes and brain), and in some reported cases, blood taurine levels were found to be low.

*Note: This test usually costs around $500. So this may not be practical for you to do proactively as a screening test. However, if your pet is on a grain-free diet — especially one that contains peas, lentils, chickpeas, or potatoes (dietary ingredients that the cases currently under investigation all had in common) — and you can afford the testing, it could save you some heartbreak (and additional money) down the line.

And, if you or your vet report these results of the blood taurine level testing to the FDA, along with additional information about your dog and the food you've been feeding them, you could also be contributing to the important body of data that could help the FDA in their investigation to get to the bottom of this issue.

two dogs eating and one is interested in the other dogs food

Consider Changing Foods

Until such time that a potential link between feeding grain-free and DCM is disproven, consider switching your dog to a more traditional, grain-containing diet. In fact, many of the cases in the FDA report improved their heart health and function with treatment, including a transition to a grain-containing diet.

When you are trying to decide what diet is best for your dog, I would recommend consulting with your veterinarian (they know your dog’s medical history) or a veterinary nutritionist.

This article will help guide you on what questions are important to be asking when selecting your dog’s food. And don’t forget that diet transitions should ideally be done gradually.

About the author

Profile picture for Dr. Beth Turner

Dr. Beth Turner

Beth Turner is a veterinarian with over 20 years of experience. She graduated from North Carolina State College of Veterinary Medicine and following graduation, she began her career as an associate veterinarian and worked closely with the local shelter.

In 2007 she accomplished her dream of practice ownership, designing and building her own clinic. Another meaningful role, while running her clinic, was serving as her county's shelter veterinarian. This gave her the opportunity to help improve the lives of many animals in her community as well as work with the rescue she loved. She sold her practice in 2019 to move across the country.

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