Are Dogs Omnivores or Carnivores - and does it matter?

The question of whether a dog is an omnivore or carnivore usually comes up because a dog owner is trying to figure out the appropriate diet, the best diet, for their dog.

An omnivore eats a combination of plant matter and animal matter while a carnivore primarily eats a meat diet.

As a result of recent DNA testing it is believed that todays domesticated dogs are descended from a line of wolves, similar to the Gray Wolf, that are now extinct. Wolves are classified as Carnivores and since dogs have descended from thousands of years of wolves it would be logical to assume they are carnivores also.

Nuclear DNA can be manipulated to get a Wolf to eventually look like a Yorkie because each sex contributes a strand of DNA to the process.

The Mitochondrial DNA is only passed on by the female so it has remained constant over thousands of years and is 99.8% identical to a 25,000 year old Gray Wolf.

Mother Nature has designed wolves, through their Mitochondrial DNA, to eat meat and she has not changed her mind, or their Mitochondrial DNA, in over 25,000 years.

However, a few thousand years ago some wolf/dogs began hanging around people. They are an intelligent species and very social so it's easy to imagine people raising some orphaned wolf pups, that eventually became multiple generations of wolf/dogs that had never known any reality other than being raised by humans, and who identified with the humans as their "pack". They warned the humans of intruders, helped protect their villages, and shared their food, which was primarily meat from animals the people had hunted and eaten themselves.

Eventually humans started cultivating plants more and more to subsidize their food supply, but dogs still preferred meat, as they do to this day, and it is likely that their families deferred to the dogs preference for meat and fed them the animal leftovers from their meals. That all began to change after the second world war.

After the war the country had thousands of silos filled with corn, wheat, grain, and plant products that had been built up for the war effort and rather than throw it away they decided to put it into dog food.

Nature gives animals the natural instinct they need to know what is good for them to eat, and what is not, through their sense of smell and taste. Where wolf/dogs are concerned their natural instinct directs them to eat meat and animal sourced protein. 

If you drop a couple hamburgers on the floor next to a pile of corn or grain, I think it is a safe bet your dog will eat the meat and ignore the grain. To get a dog to eat grain it has to be flavored to smell and taste like meat, thus fooling the natural instincts Mother Nature gave your dog to stay healthy.  

Nutritionists and dog food companies, and any veterinarians that listen to them, are claiming dogs have developed an increased ability to metabolize grain and high-glycemic carbohydrates (which is true to some degree) and that means dogs are now omnivores, and carbohydrates are completely healthy for them to eat, in any amount (which is not true). 

The rationale that the ability to metabolize carbohydrates = all carbohydrates are healthy for dogs to eat in any quantity in falacious. Falacious = False! Pure rubbish.

Can certain carbohydrates be included in a well balanced dog food successfully? Absolutely, but it comes down to a fine balance and it depends on the carbohydrates and their Glycemic Index which reflects the rate they trigger blood glucose to spike. Spiking is not good and those high-glycemic carbs should be avoided whether the dog can metabolize them or not. 

Dogs do not need carbohydrates to produce blood glucose the way humans do. Humans convert carbohydrates into blood sugar, a necessary energy for the body, but dogs convert protein and fat into glucose (a process called gluconeogenesis) so they do not need carbohydrates. 

Dogs have no nutritional need for carbohydrates, none, a fact that nutritionists acknowledge. Dogs get their blood glucose from meat and fat which is much healthier because they do not spike blood sugar no matter how much the dog eats. Carbohydrates on the other hand can and do cause blood glucose to spike.

While it is true that dogs have developed an increased ability to metabolize carbohydrates it does not follow that carbohydrates in amounts as high as 55% to 75% can be introduced into the diet of animals whose system was designed and has been functioning for tens of thousands of years eating and digesting meat and very little, if any, carbohydrates. 

These days, dog food can have as much as 55% to 75% carbohydrates in it. The less expensive dog foods are nothing but grain and carbohydrates flavored to smell and taste like meat. A human child can metabolize a cold cereal like Cherios, but that does not imply that a diet of 75% Cherios would be healthy.

The argument that the ability of a carnivore to metabolize a carbohydrate automatically means it is nutritious for that animal to eat any quantity of it is not one I would expect a competent nutritionist to make. 

Dogs were not designed to eat high-glycemic carbohydrates like potatoes, sweet potatoes, and grain whether they have developed the ability to metabolize them or not. They were not designed to eat a diet with protein that was predominantly sourced from vegetables. Hanging around humans and eating some of the food they eat over a couple hundred years does not change their Mitochondrial DNA and what they were designed to eat, which is predominantly animal protein and fat.

Because a dog will gulp down a pancake that hits the floor does not indicate that it is healthy for them to do so. In fact eating grain, potato, and sugar will definitely have a detrimental impact on your dogs gut over time and your dogs overall health, as we have observed with hundreds of dogs that we saw in our dog food store over fifteen years.

Lisa M Freeman, DVM, PhD, nutritionist at Tufts in FINDING THE BEST FOOD FOR YOUR PET, PETFOODOLOGY BLOG on June 4, 2018 published the following, and I quote: 

"And while grains have been accused on the internet of causing nearly every disease known to dogs, grains do not contribute to any health problems and are used in pet food as a nutritious source of protein, vitamins, and minerals." (The emphasis is mine).

When nutritionists make statements so far removed from easily observable reality it is no wonder people are turning to the Internet in search of more reliable information.

Obesity in dogs is now estimated to be in excess of 60%, a situation the referenced nutritionist recognizes as a "health problem" but apparently does not think there is any connection between the copious amounts of high-glycemic carbohydrates in dog food and all the overweight dogs.

Academic 'experts', prone to build and live in theoretical castles, are often out of touch with practical reality, by generally limiting what they accept as reality to peer reviewed papers.

Simply running a test to determine if a dog can metabolize a food without doing continuing research and observing real life dogs to see how the entire system is affected by the change in diet falls way short of the mark, especially if you have the dogs best interests at heart rather than the multi-billion dollar company that is paying for the research. 

A diet loaded with 50 to 75% carbohydrates is not the diet that Nature intended nor is it one that is healthy despite the vociferous arguments by nutritionists who have apparently been taught the only criteria to determine if a food is healthy is whether the dogs system can metabolize it or not. 

For one thing the excess carbohydrates raise the blood sugar levels significantly (which eating meat does not do) and triggers the release of insulin from the Pancreas, which tells the body to store the excess sugar in the liver, and eventually ends up in muscle tissue as stored fat, resulting in an abundance of overweight dogs.

It's entirely possible that this overstimulation of the pancreas eventually leads to the frequency of pancreatitis in the dog population, due to the addition of grain, etc since eating meat does not cause a jump in the blood sugar.

Another problem these high-glycemic carbohydrates cause is upsetting the balance of harmful bacteria to beneficial bacteria in the Microbiome in the gut by feeding the pathogenic (bad) bacteria which grows faster than the beneficial bacteria and overpowers it which causes a state of dysbiosis, and can lead to "Leaky Gut" and "Systemic Candida".

Most nutritionists and Veterinarians are unaware of Leaky Gut, what causes it, and how to resolve it. The normal claim being there is no proof that such a condition exists. 

The state of mind that refuses to honor empirical data collected through direct observation, and does not accept any data that is not peer reviewed with a direct causal relationship to the problem is short sighted and usually only works in the simplest of situations.

In the case of "Leaky Gut" the pathway is a complicated, convoluted one that is hard to trace to a single cause and sometimes, in looking for a solution, it helps to acknowledge the problems that do exist and try working back to the cause from there.

“We don’t know a lot, but we know that it exists,” said Linda A. Lee, MD, a gastroenterologist and director of the Johns Hopkins Integrative Medicine and Digestive Center when asked, not long ago, about Leaky Gut. 

Leaky Gut is real and is responsible for various problems including food intolerance or Food Allergies, auto-immune problems caused by an overworked immune system, and Systemic Candida, in which the Candida Albicans yeast/fungus leaks out of the gut and spreads to the rest of the body through the blood stream, causing no end of skin problems and imbalances.

There are multiple factors that can contribute to Leaky Gut but the primary one is an excess of high-glycemic carbohydrates. They feed the negative bacteria which overpower the beneficial bacteria in the gut microbiome creating a state on dysbiosis that can lead to Leaky Gut.

Often there are other causative factors that combine to accelerate the development of Leaky Gut like antibiotics (that kill off the beneficial bacteria as well as the harmful bacteria), heavy metals, toxins, and GMO's with pesticides. However, the effect of high-glycemic carbohydrates on the Candida Albicans fungus, which grows back faster than the beneficial bacteria after the use of antibiotics, is a primary causative factor.

We have affirmed this with a diet designed by a PhD Animal Nutritionist with his PhD in gut biology, that has no grain or potatoes in it and has successfully resolved Leaky Gut and Systemic Candida for the last fifteen years - not a theory - fifteen years of actual real world success.

It is balanced on a calorie basis with the calories of fat and protein usually being equal and the carbohydrates about a third or less.

While many are still denying, saying there is no proof, or simply ignoring the problems, we have been using a diet for fifteen years that actually works, and its success points a way toward an understanding of the causes. The use of empirical evidence is a valid way to gather information that can help direct future research and help clarify the problem. 

I'm not saying that carbohydrates cannot be successfully integrated into dog food but I do think it crucial that they be used sparingly with attention to balancing the overall nutrient profile and lowering the glycemic index to integrate them into a dogs system that is apparently still more of a carnivore than an omnivore.

Trying to prove dogs can eat any amount of carbohydrates because of a few focused tests on metabolism is using science to force an agenda that does a disservice to all involved, especially the dogs.

As for whether your dog is classified as an Omnivore or Carnivore I do not think it matters to the dog as long as you feed it like it is primarily a Carnivore. See the following blogs on feeding young dogs and aging dogs.


Written May 15, 2023 

by Richard Darlington, CEO

Brothers Dog Food, LLC