Dogs and Grain Free Diet

February 10, 2022
Diana Bocco
Reviewed By: 
Dr. Farshad Goodarzi - Animal Nutritionist
5 minute read
Confused dog about grain free dog food

Grain-free dog diets have been around for a long time, but they have become increasingly popular over the past decade. The trend to feed dogs grain-free diets seems to somehow coincide with the popularity of low carb and keto diets that have become the go-to solution for weight loss among people.

A grain-free diet for dogs is basically one that contains no grains of any kind. This means no corn, wheat, rice, millet, rye, soy, barley or oats. Grains gained a bad reputation over the years because cheap kibble often contains a big percentage of cheap grains (primarily corn), which is used to replace quality ingredients and bulk up the food.

But this doesn’t necessarily mean all grains are bad or all grains are the same when used as part of a healthy, well-balanced diet. Grains provide fibre, which aids digestion, helps keep the colon healthy, and can prevent obesity by making your pup feel full so he eats less. They also provide plenty of energy and are great for active or sporty dogs as well as growing puppies.  

An important thing to keep in mind is that grain-free does not mean carbohydrate-free. Most dry dog foods substitute grains with other carbohydrate sources. According to PetMD, potatoes, sweet potatoes, peas and lentils are some of the most common sources of carbohydrates in grain-free dog food. Some brands also use quinoa.

Are Grain-Free Dog Diets a Good Thing?

The simple answer is, it depends. There’s a lot of information out there so let us break it down into digestible pieces!

You might have heard that in 2018, the FDA announced that it was researching a potential link between grain-free foods and Canine Dilated Cardiomyopathy (DCM). This research seems to have actually started with a study conducted by Kaplan [GBF1] et al., 2018[GBF2]. DCM is a heart condition that affects the heart muscle and can result in congestive heart failure. Large and giant breeds (such as Doberman Pinschers, Great Danes, Newfoundlands, Irish Wolfhounds, and Saint Bernards) are more likely to develop this condition, but the FDA started receiving reports of DCM happening in smaller breeds, so they decided to take a closer look.

Turns out DCM seemed to be appearing more regularly in dogs eating certain grain-free foods. Upon closer inspection, it seemed this was specifically related to grain-free foods containing “a high proportion of peas, lentils, other legume seeds (pulses), and/or potatoes in various forms (whole, flour, protein, etc.) as main ingredients (listed within the first 10 ingredients in the ingredient list, before vitamins and minerals).”

Kaplan et al., 2018 study reported that “certain diets and diet characteristics were associated with the development of taurine deficiency.” This is an important piece of information to hold on to! One thing to keep in mind is that taurine deficiency, food digestibility, and genetics have been known for many years to lead to DCM in dogs and cats.

In dogs, taurine is synthesized primarily in the liver and central nervous system from methionine and cysteine which are normally supplied by food. Actually, dogs can produce enough taurine for themselves if enough methionine and cysteine are biologically available for them. But if enough amounts of methionine and cysteine are not biologically available for them, taurine deficiency will appear.

In June 2019, the American Food and Drug Administration made headlines when it linked 16 brands of dog food to DCM. 90% of the pet food brands named in the report were considered “grain-free”. These grain-free foods contained no wheat, corn, soy, rice, barley, or other grains but most did contain, in the words of the report, a “high proportion of peas, lentils, other legume seeds (pulses), and/or potatoes in various forms (whole, flour, protein, etc.) as main ingredients.“[GBF3]  

So what does this mean? Does it mean legumes or potatoes are dangerous and can lead to DCM in our dogs? The answer is definitely NO. It is all about diet formulation and supplying the right amount of nutrients in a balanced manner. In other words, some of the legumes are known to be deficient in methionine and cysteine and if they are the only source (or the main source) of protein in your dog’s food, they can cause problems. Many dog food producers try to supply the protein requirements of your dogs through cheap protein sources including plant-derived proteins like legumes and animal by-products. Therefore, some of them end up with methionine and cysteine deficiency in their food which leads to taurine deficiency in your dog. So the problem isn’t the ingredients on their own but how they have been formulated in diets.

Scientist dog sitting behind microscope and testing vials

Now let us make the argument for why legumes and good carbs should be a part of your dog’s diet IF FORMULATED CORRECTLY!

We know now that the life expectancy of dogs decreases if fed only meat (or even animal-derived protein sources) for extended periods of time. Proteins and amino acids along with fats and carbohydrates are the major macronutrients in food. Proteins and amino acids are needed to form the basis of living tissues in your dog’s body. They also play a central role in the biological processes and activity of many important biochemical compounds in your dog’s body like hormones, enzymes, immune system-related components, brain chemicals, etc. Your dog also needs energy for maintenance (maintaining body size, body composition and a level of necessary and desirable physical activity consistent with long-term good health), growth and development, etc.

Easily digestible carbohydrates (like gelatinized starch found in cooked grains, legumes and potatoes) and fats are the main sources of energy in dog food. Inadequate energy in food through deficiency of dietary fat or carbohydrates leads to poor growth, weight loss, and reduced physical ability and reproductive performance. Dietary carbohydrates deficiency makes the body of your dog draw more heavily on its protein supply (and deposit) to meet its energy needs. When dogs are fed with diets high in protein but low in energy diets (energy-deficient diets), part of the protein is metabolized and used for energy production. The nitrogen part of this protein portion is not used for energy production and needs to be converted in the liver to certain components and sent out of the body by kidneys, which means severe stress on the liver and kidneys. Now that’s definitely not good!

As long as the dog’s supply of protein is sufficient, using proteins for energy production does not lead to protein deficiency for your dog but more stress for her/his liver and kidneys is certain.

As you see, although a food can consist of only meat (or even animal-derived protein sources) is grain-free and also legume-free, your dog can still end up with serious health issues.

The fact is all of these food ingredients can and should be a healthy part of a diet for dogs, but they must be human-grade, hygiene and fresh and mixed in a well-balanced manner to supply your dog’s requirements individually. This is why we’re such big advocates of individualized fresh diets for our dogs formulated by qualified professionals.

Also when it comes down to ingredients, according to Best Pets Veterinary Hospital, brands of dog food that use lots of cornmeal or wheat gluten as a cheap way to bulk out their products are in essence creating a lower quality product. If you see that listed within the first five ingredients of the dog food you’re feeding, it’s time to switch to something better. But even if it’s down on the list, these fillers offer little to no nutritional value so there’s no reason for them to be part of your dog’s diet.

When in doubt about the pros and cons of grains in dog food, it’s always better to speak to your veterinarian for better advice.

Happy dog eating grain free fresh dog food

Should You Feed Your Dog a Grain-Free Diet?

If you are thinking of switching your dog to a grain-free diet or already feeding one, you should discuss the potential risks and benefits with your vet. This is especially important if you have a dog with an underlying or chronic health condition that might be affected by diet.

Otherwise, grain-free diets can be helpful in certain situations.

One of them is allergies, although grain allergies are rare and when they do happen, the main culprit is almost always corn. Dogs are more likely to be allergic to proteins, with chicken and then beef being the two main culprits. Food allergies are also very tricky to diagnose and usually require a long process of strict elimination where the animal is fed a single protein and single carbohydrate at a time to observe the body’s response.

Overweight or obese dogs might also do better in a grain-free diet, as the lack of carbohydrates means the body needs to burn fat as a source of energy. The result? Your pup might lose weight more easily on a grain-free diet. Keep in mind that grain-free might also mean low fibre unless the food has added different carbs to supply that. Since fibre plays an important role in helping your pup feel full, you might end up with a hungrier dog otherwise.

According to DVM360, a diet containing at least moderate levels of fibre is a good “way to reduce the caloric content of a weight loss diet” while keeping your dog full.

Finally, a grain-free diet could also benefit pets with cancer. Cancer is the leading cause of death among dogs, with 45 percent of dogs over 10 years of age dying of cancer.  Generally speaking, carbohydrates “feed” cancer cells by providing plenty of glucose but also stimulating insulin production -- which then speeds glucose absorption and could cause cancer cells to reproduce faster.

Both in human and canine cancer patients, this means reducing carb intake could slow down the spread of cancer. On the other hand, a low-carb, high-fat diet seems to promote remission and increase survival time.  If your dog is undergoing chemotherapy or has other underlying health conditions in addition to cancer, you should discuss options with your veterinarian before switching to a high-protein, grain-free diet.

Grain-free diets could offer relief in other situations as well, such as in the case of dogs with chronic gut inflammation or those with diabetes. Again, this depends on a lot of factors, such as what other health issues your dog might be experiencing or potential side effects of the medication he could be taking. Never switch diets without talking to a vet first if your dog is sick.

Cola's Kitchen fresh dog food in a bowl

What About Fresh Food?

Nutrition plays a key role in the overall wellness of our canine companions, so the better quality food you can offer, the healthier and happier your dog will be as a result.  

Fresh food has become a popular choice for dog parents who are concerned about feeding the very best available. Whole food, clean diets with no added artificial coloring or preservatives aren’t just a better choice but they also take the guessing of “carb or no carb” out of the equation.

A fresh diet provides many benefits, including better overall health, better digestion, increased energy levels, and a healthy and shiny coat. You can learn more about the many benefits of feeding a well-balanced fresh diet in our article, What to Expect When Switching to Cola's Kitchen Individually Balanced Fresh Dog Food?

Kibble is -- as you’ve learned by now --often filled with lots of empty carbohydrates as a replacement for better-quality ingredients. To avoid those poor quality carbs, many pet parents opt for feeding grain-free diets -- which is not always the best choice for every pet, as carbs do provide a number of vitamins and plenty of fibre to keep your pup healthy.

A healthier way to feed carbohydrates is to feed fresh food. Individually balanced fresh dog is tailor-made for a dog based on his age, breed, body weight and condition, and other factors. And because all food is fresh and human-grade, adding carbohydrates into the mix is never a problem. At Cola’s Kitchen, we only use high-quality grains such as brown rice and organic quinoa. We also add other healthy carbohydrates, including sweet potatoes, green lentils, green peas and beans.

about cola's precision diet

Cola's Kitchen precision diet is the first truly tailored diet for a unique approach to nutrition. Our diets are individually formulated and balanced to address the most precise nutritional requirements of your pup.

learn more
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.