Are Corn, Wheat, and Grains Really Bad For Your Dog?


Yesterday in my post about Jet’s veterinary history, I mentioned that he is a corn-free and wheat-free dog.

The reason for Jet’s corn-free, wheat-free status is entirely due to his inability to process these ingredients.

What does this mean?

It means that when fed foods containing corn and wheat, Jet poops at LEAST five times a day. Each poop filling a plastic grocery bag…it’s not pretty.

But with Jet’s special needs aside, a lot of you are asking if corn, wheat, and grains really are bad for your dog.


Your Dog and Wheat

Recent trends in the pet food industry have moved towards wheat-free, corn-free, and grain free dog foods.

As pet owners, we are encouraged to buy these foods because they are “healthier.” Some companies even claim that they are closer to what our dogs eat in “the wild.’

Is there any truth to this dietary approach, though? Is it really a healthier approach to feeding our dogs? Is it anywhere close to what our dogs would eat “in the wild?”

Is it really a healthier approach to feeding our dogs? Is it anywhere close to what our dogs would eat “in the wild?”

The “In the Wild” Argument

Even if the dog foods produced by these companies were what our dogs would eat “in the wild” (have you ever seen a wild dog eat kibble in the wild?), we have to address a rather glaring fact – our dogs – our Labradors, our huskies, our corgis, our chihuahuas – they aren’t living in the wild.

In fact, while the time of origin of domesticated dogs is somewhat cloudy, at least 12.500 years of domestication have gone into canid domestication. This means that for more than 12,000 years, evolution has influenced the nutritional needs and digestive processes of dogs.

So, while our domesticated dog’s ancestors may have eaten a diet that was low in starch content, this is not necessarily what is best for our dogs today. In fact, a very interesting article on Live Science a few years ago covers a study that looked at the genomes of domestic dogs and found that they were better equipt to survive and thrive on starches versus their ancestors.

So, while the claim may be that our domesticated dogs should eat a diet that is comparable to their ancestors, genetic studies seem to prove otherwise. Essentially, through the process of domestication, we have caused the domestic dog’s digestive system to evolve to adapt to a more “human-like” diet.

This evolution makes sense if you consider it. Over twelve thousand years ago, dogs chose us as companions because of the food supply we had to offer. They stuck around for the free food and in the process they submitted to our domestication. Over the years, however, our own diets shifted from that of hunters and gatherers to that of a more agricultural and settled society and as our companions, the same was true for domestic dogs.

So, what does this really mean in terms of grain-free dog food?

Just Because It’s Usable Doesn’t Mean It’s Optimal

Just because a body is able to utilize a specific nutrient for fuel, does not mean that that particular nutrient is optimal.


Every living thing depends upon macronutrients, vitamins, minerals, and water to survive and we rely upon food and water to obtain those things.

Humans, for example, require three major macronutrients in order to function – protein, carbohydrates, and fat. Protein provides essential amino acids that our bodies require in order to repair and build new cells. Carbohydrates provide an easily accessible source of energy which fuels the basic functions of the body. Fats provide energy when carbohydrates are unavailable, they provide a cushion over our internal organs, they assist in cell growth, they help in the production of certain hormones, and they help us to absorb certain fat-soluble nutrients.

We are able to obtain all of these nutrients through the foods that we eat.

Different foods provide varied amounts of macronutrients, vitamins, and minerals.

Twinkies, for example,  can provide carbohydrates and fats that can be used as a source of energy. The ratio of nutrition in Twinkies, however, is quite low, and the simple carbohydrates (sugars) that provide us with energy are quickly burned through leading to a rapid sugar peak and a sudden sugar crash. To solve this, we turn to more nutritionally sound foods that provide more nutrition per calorie of energy, foods that burn slower and provide a more stable source of energy. Whole foods like fruits and vegetables, whole grains (complex carbohydrates,) and lean proteins.




How Does This Apply to Your Dog and Grain-Free Foods?

Just like people, dogs require proteins and fats for optimal functioning. Dogs have no necessity for carbohydrates, however, their affordability and our dog’s ability to use carbohydrates for energy generally means including carbohydrates in foods.

With this in mind as well as the fact that, like people, dogs also require nutrient-dense foods that provide the most “bang for their buck,” you should be paying more attention to the quality of nutrition in your dog’s food, rather than to obsessing over being “grain-free.”

Simply put, you should be making sure that you aren’t feeding your dog “Twinkies” instead of trying to make your dog an Atkin’s dog.

Not All Ingredients Are Created Equal

So grains are good…right?

Well, yes and no.

Remember above when I mentioned simple carbohydrates and complex carbohydrates? When humans consume simple carbohydrates we burn through the energy that they provide quickly, whereas complex carbohydrates break down much more slowly in the body and provide a slow and steady release of energy.

The same principle applies to the ingredients in your dog’s food. Refined and simple grains provide your dog with a short lived source of energy. More complex or “whole” grains, on the other hand, provide a longer lasting energy source.

So what are the “good” grain sources to look for? Any grain that has not been refined to remove the bran, germ, and endosperm, is a good source of long-lasting energy. These also provide a good source of B-vitamins and fiber in your dog’s diet. The most notable sources of whole grains in dog foods are WHOLE wheat and corn (just PLEASE make sure your ingredients are ALWAYS U.S. sourced.)

What are the “bad” grain sources to avoid? Milled grains that have removed the “extras” from the grain fall into this category. Most notably, white rice falls into this category. (Note – we feed white rice when our dogs are ill because it is easily digested and provides plenty of water content as well.)

So What Can You Take Away From This?

Focus less on the concept of being “grain free” and more on the quality of the ingredients in your dog’s food.

If you can afford to feed a raw diet, my personal opinion is that it is the best way to go. A diet packed with whole and healthy food that can be easily utilized for energy is always the better choice. Just be sure when feeding raw that you include plenty of variety and either a whole prey model or supplement with fruits and vegetables for vitamin and mineral content. For most households, however, raw just isn’t an option.

If you want to feed kibble and you want to go grain free, go for it! A grain free choice is going to contain more protein and fat which provide your dog with what they need energy wise – just make sure that your ingredients are whole and healthy.

Now, if you can’t afford to go grain free, don’t panic. Your dog is perfectly capable of utilizing most grains and carbohydrate sources for nutrition. Just try to stick with whole grains and make sure that the food you are feeding has plenty of other whole and healthy ingredients.


The bottom line? Feed whole healthy ingredients and avoid Twinkies at all costs.

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