Is Grain Free Food Better for Dogs?


This article is written by Pet Circle's qualified veterinarian, Dr Kim Chainey, and last updated by Dr Gillian Hill, BVSc.

Grain free dog food has become increasingly popular in the pet food industry in recent years, mirroring trends in the world of human nutrition. The popularity of grain free diets has led to an enormous increase in the number of brands and varieties available. How do you know if a grain free diet is better for your dog? And how do you choose the best one? Read on to find out!


What does Grain Free mean?

Grain Free Food Benefits

Drawbacks of a Grain Free Diet

What Should You Look for in a Grain Free Food

Further Reading

What is a grain free dog food?

Put simply, a grain free diet is a diet free from all grains, including ingredients such as wheat, corn, rice, oats and barley.

Is feeding a grain free diet really better for your dog? Let's firstly talk about the nutritional benefits of grains.

Grains contribute valuable nutrients including vitamins, minerals, fatty acids and fibre to the diet. At the same time, they help to keep the fat and calorie content lower than if animal products were used in their place.

If we decide to feed a grain free diet, we need to ensure we can still provide these key nutrients or 'building blocks' that make up a complete and balanced diet.

Benefits of Grain Free Diets

There are several arguments put forward by advocates of the grain-free movement, and we'll explore them below.

Grain free diets more closely replicate a natural diet

One big argument put forward by fans of the grain free movement is that as carnivorous animals, grains hold no place in the natural diet for dogs and cats. While cats are obligate carnivores, meaning they must eat meat, technically domestic dogs are omnivores. Dogs have lived alongside humans for tens of thousands of years eating our scraps and cast offs, including meats, vegetables and you guessed it - grains! If we compare the genome of a dog to a wolf, it's been shown that dogs do have the ability to digest the starches found in grains. In fact, a microbiology researcher in 2012 found that dogs have multiple copies of the gene coding for the digestive enzyme, amylase, which is synthesised by the pancreas. While dogs can have anywhere from 4 to 30 copies of this gene, wolves only have 2 indicating a reduced ability to digest starch. While their distant relative may be the wolf, the domestic dog's digestive system has undoubtedly changed a lot since then.

This comes down to the distinction between nutrients and ingredients. Cooked grains such as rice and corn contain valuable nutrients such as proteins, carbohydrates, vitamins, minerals, fatty acids and fibre which, believe it or not, are very beneficial and able to be absorbed and utilised by both cats and dogs. So it's not all about the ingredient, for example wheat, but instead the nutritional benefit that that ingredient provides.

While the quality and type of ingredients used in your pet's food certainly matter, it's the nutrients contained within these ingredients that your pet will use to fuel their bodies.

Grain free diets are beneficial for food allergies

The second argument put forward in favour of grain free diets is that they often manufactured with a holistic focus and can include nutraceutical ingredients and superfoods that could offer additional beneficial nutrients. Although not suitable for use as a blanket hypoallergenic diet for dogs, grain free diets may be suitable for dogs with allergies to grain based proteins such as wheat and corn.

Keep in mind that grain allergies in pets are extremely uncommon, and it's far more likely for dogs and cats to be allergic to the protein source within the food. While many parents do report that their pets skin and/or digestive symptoms improved when they were switched onto a grain free diet, we don't know whether this was because the diet was free of grains, or simply because the protein source was different. It's common for manufacturers of grain free diets to select exotic and 'novel' protein sources such as bison, lamb and kangaroo. Because it's relatively unlikely for pets to be allergic to these new and exotic protein sources, switching pets to one of these grain free diets may lead us to believe that the grains were the culprit.

So is grain-based nutrition ideal and biologically appropriate for dogs and cats? Not necessarily, but on the flip side it doesn't automatically mean that it is harmful.

What are the drawbacks of a grain free diet?

  • More expensive - less cost effective carbohydrate source such as sweet potato or tapioca flour need to be used to replace the grain
  • Carbohydrate alternatives can offer less in the way of beneficial nutrients - brown rice is an excellent source of fibre and slow release energy while tapioca flour is highly starchy and contains virtually no fibre
  • More energy dense - must pay close attention to feeding amounts to avoid weight gain and obesity

Does Grain Free Food Cause Heart Disease?

In the last few years, veterinary cardiologists in the United States reported increased rates of a deadly heart condition, dilated cardiomyopathy (DCM), in Golden Retrievers and breeds which are not typically predisposed to DCM. Frequently these dogs were noted as being fed 'boutique, exotic or grain free' diets, or BEG diets for short.

At this stage, research is still ongoing and it is unclear as to the underlying cause of the reported cases of diet related DCM. Some possible theories include nutritional imbalances in the foods themselves, unknown effects of certain exotic ingredients such as legumes, fruits, flaxseeds etc, or even potentially an unknown toxin.

For pet parents concerned about nutritional deficiencies, feeding a rotational diet may help. A rotational diet offers a your dog with some variety while also reducing the risk of a deficiency developing from feeding a particular diet over an extended period of time. Rotational feeding involves offering your dog a combination of high quality diets, ideally varying protein sources and formats (eg. dry, freeze and air dried, wet). For more information, take a read through Rotational Diets for Dogs.

What should you look for in a grain free food?

While many grain free foods are nutritious and balanced, they are not all created equal. When looking for a grain free food for your pet it is important to critically evaluate the ingredients and nutrients that it provides. For more information about the ingredients in pet foods and how to read labels, take a read through Pet Food Ingredients and How to Read Pet Food Labels.

Your choice of food will also depend on your dog's life stage, and any other conditions which impact your dog's nutritional needs, including weight management and food allergies.

Our Top Picks for Grain Free Dog Foods:

A final word about grains as 'fillers'

Don't be tricked into the marketing of grains as 'filler' ingredients. We talked about the key nutrients that grains provide and that scientific studies have shown us that dogs are actually very efficient at both digesting and utilizing these nutrients found in grains. In carefully balanced amounts, grains add valuable vitamins, minerals, fatty acids and fibre to the diet. Now that's food for thought!

See All Grain Free Dog Foods

Further Reading

Want to know more? Take a look at our other articles:

Premium Pet Food: Is it Worth it?

How to Introduce a New Food to Your Pet

Breed Specific Dog Food Guide

Raw Diets for Pets

Shop All Dog Supplies Now