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September 7, 2021

Grain Free or Grain Inclusive?

  • Grain-Free
  • Grains
German Shepherd dog sitting in grassy field

Grain-free diets are commonplace in the pet food aisle. There are several reasons for this category of pet foods, including the belief that grains are harmful for pets and that grain-free diets are more appropriate for dogs and cats from an evolutionary perspective.

What are grains good for?

Grains are an important source of complex carbohydrates, which are more slowly digested compared to simple carbohydrates. Although carbohydrates are not considered essential nutrients in the diets of dogs and cats and are often mislabeled as “fillers,” they do play a critical role in your pet’s body. In particular, carbohydrates provide a highly digestible, readily available energy source. Foods which are rich in complex carbohydrates are also an important source of essential nutrients. The shape, texture and density of kibble and wet food also depend on the carbohydrate (starch) content of the food. This is important, as mouthfeel and the structure of food help to determine palatability.

Can dogs and cats use carbohydrates from grains?

Yes! Recent genetic research suggests that one of the important steps in the domestication of dogs was their adaptation to a diet higher in carbohydrates relative to the diet of carnivorous wolves. Although carbohydrates are not considered essential for cats, research suggests that moderate amounts may actually be beneficial in promoting insulin sensitivity. Another benefit of dietary carbohydrates is that they, along with fat, are body’s preferred source of energy; using protein as an energy source can be inefficient and expensive, both metabolically and environmentally.

Some of the grains commonly found in pet foods

  • Barley
  • Corn
  • Rice
  • Oats
  • Millet

Whole grains include all parts of the grain, while refined grains have the nutrient-rich germ and bran layers removed. Whole grains support digestive health since they are not only an excellent source of complex carbohydrates but are also rich in fiber. Dietary fiber is a unique type of carbohydrate that cannot be digested by your pet’s digestive enzymes, but nonetheless provides many benefits. For example, oats and barley contain a special type of fibre called beta-glucan, which has been shown in numerous human studies to fight heart disease and diabetes. Beta-glucan may also be beneficial in pet foods to help support a healthy weight.

My pet is allergic to grains, what are my options?

Some pets may have intolerances to one or more specific grains, but it might not be necessary to eliminate all grains. Grain-free does not mean carbohydrate-free, as complex carbohydrates are found in many non-grain ingredients such as peas, lentils, chickpeas, tapioca, potatoes, and sweet potatoes.

Gluten-free diets are necessary for humans diagnosed with celiac disease or nonceliac gluten sensitivity, but this is not a common problem in pets and most tolerate gluten without any difficulty. The exception is some Irish Setters with inherited gluten sensitivity.
Theresa Lantz
Theresa LantzCompanion Animal Nutritionist

Many grain-free pet foods are higher in protein than their grain-inclusive counterparts. Since all foods contain a balance of carbohydrates, fat, and protein, decreasing the amount of carbohydrate in a food will increase the fat and/or protein content. While extra protein is typically not a problem for most healthy pets, it can be problematic in certain medical conditions such as later stages of kidney disease, or pancreatitis in the case of increased fat.

What are some of the benefits of grain-free carbohydrate sources?

Pulse ingredients such as lentils, peas and chickpeas are an excellent source of complex carbohydrates, fiber, vitamins, and minerals, and provide most of the essential amino acids required by dogs and cats. Uniquely, peas provide an added environmental benefit in that they are used as a tool in sustainable agriculture to add nitrogen back into the soil.

Potatoes are a rich source of essential vitamins and minerals, particularly vitamin C and potassium. Cooked potatoes are also rich in prebiotic fiber which can support a healthy gut microbiome and good quality stools.

Dog and owner at farmers market

Tapioca provides a novel source of energy and does not contain protein, so it is not typically considered a potential allergen or source of food sensitivity. This is especially important in limited ingredient diets that are designed for pets with sensitivities.

So, what’s the right choice?

Overall, there is no ‘right’ choice - only the best choice for you and your beloved cat or dog. Both grain free and grain ingredients offer many health benefits and can be used to make a safe, healthy, complete, and balanced diet. Below is a small overview of some popular grain and non-grain ingredients along with their benefits.

Benefits of Grain Ingredients



Fiber Type



Vitamin B1, zinc, magnesium

Soluble & insoluble, prebiotic

Beta-glucan, gluten-free


Vitamin B1, B2, manganese

Soluble & insoluble, prebiotic

Beta-glucan, ancient grain



Soluble & insoluble, prebiotic

Ancient grain, gluten-free

Benefits of Non-Grain Ingredients



Fiber Type



Amino acids, vitamin E, zinc

Insoluble, soluble & prebiotic

Good source of polyphenols (antioxidants), gluten-free


Amino acids, manganese, zinc

Insoluble, soluble & prebiotic

Good source of polyphenols (antioxidants), gluten-free


Iron, vitamin B1, B3, magnesium, potassium

Insoluble, soluble & prebiotic

Cooked potatoes a good source of prebiotic fiber, gluten free

This article originally appeared on

This article was originally published April 8, 2016. Refreshed September 2021.


Theresa Lantz

Theresa Lantz

Companion Animal Nutritionist

Theresa received both her BSc in Companion Animal Health and MSc in Animal Science from the University of Alberta.