I thought this matter had been settled! However, I recently ran into a couple of articles arguing that dogs were omnivores. This idea has perplexed me for years. Internally, regardless of how differently dogs look from the outside, they have all the characteristics of carnivores. Dogs have a hinged jaw that moves up and down – not side to side, and sharp pointed teeth – not flat molars. Their teeth and jaw are meant to rip and tear meat. They are not meant to chew, grind and pulverize grains and grasses. They have a short and simple digestive tract, whereas omnivores have a longer, more complex digestive tract. Opposite of omnivores, food stays in a dog’s stomach longer and then passes quickly through its short digestive tract. Omnivores pass food to their intestines more quickly and then the food stays in their intestines longer.
I can only wonder what the motive is for claiming dogs can equally subsist on plant and animal-based foods. Could it perhaps be motivated by the pet food industry? After all, commercial pet food companies subsist on using high amounts of carbohydrates such as grains, potatoes and legumes. This is because these ingredients are necessary for maintaining a longer shelf life. Diets made from meat and fat would surely rot quickly in a bag.
One frequently seen argument is that years of eating plant materials, starches, grains and cereals have changed dogs into omnivores. But that isn’t how evolution works, at least not in thousands, or even tens of thousands of years. Simply changing the diet of a species doesn’t change them from a carnivore to an omnivore or an omnivore to an herbivore.
Genetics can cause appearance changes quickly, such as short ears to long, floppy ears or small almond eyes to round eyes and even long legs to short dwarfism legs. However, changing the internal digestive tract of an animal would take hundreds of thousands of years to change. If this could occur, many of the non-adaptive members of the species would die off. Spontaneous mutation can make small, more instant changes, but again, it would take hundreds – or in reality – thousands of years to change the entire digestive system of the species, which in this case, would include the structure of the jaws and teeth, the complexity of the digestive tract, and the enzymes needed to digest a standard omnivore diet of grains and grasses.
Recent studies have shown that dogs have more of an ability to digest starches than wolves, and both are classified in the same species. Several have taken this to mean dogs are now omnivores. But the addition of more starch enzymes copied in the pancreas, doesn’t help with dogs, or wolves, as they have no amylase in their saliva. Starch digestion starches in the mouth to help with digestion further when it reaches the stomach and then the small intestine. And even then, dogs have a short and simple digestive tract which makes the passing of the high-fiber found in starch difficult to pass and process. Because dogs have a short intestinal tract, they can’t ferment food well, so food is not further broken down in the large intestine. As a result, high-fiber diets produce large, foul smelling stools in dogs and it wastes their energy trying to digest the large mass of food, which is foreign to a carnivore’s digestive tract.
I have seen the claim that wolves eat the stomach contents of their prey in the wild. This too is incorrect. Dr. David Mech followed wolves for years to observe their habitat, hunting patterns and how they have adapted. He found that wolves consumed all their prey except the skull, which is too hard to consume, and the stomach contents, which are bitter and full of gastric juices and bile. Further studies have also shown this to be true. “Wolves do not feed on the contents of the rumen; so this, along with the larger unbreakable bones and some of the hide, are often the only things remaining when wolves and associated scavengers are done.”
Further, dogs are in the same species as wolves. They can interbreed and their DNA is so close it can’t be distinguished when they interbreed:
“Wolves (canis lupus), coyotes (canis latrans), and domestic dogs (canis familiaris) are closely-related species. All three can interbreed and produce viable, fertile offspring – wolfdogs, coywolves, and coydogs.
Through DNA analysis, scientists have established that the wolf is the ancestor of the dog. Dogs and wolves are so closely related that DNA analysis cannot distinguish a wolf from a dog or a wolfdog hybrid.”
Certainly there are some odd carnivores. One of which is the Giant Panda, which eats mostly bamboo. Through mutation, they have a gene that causes them to find meat repulsive. As a result, they are left to eat massive amounts of bamboo to survive. They lack energy due to the lack of animal protein and have to consume each other’s feces to maintain bacteria in their gut. They do possess one crushing molar which is important for starch digestion. Dogs do not have any flat molars so they are unable to fully pulverize plant materials to help with digestion. Additionally, dogs do not produce any amylase in their saliva which is needed to start the digestion of starches.
“Genome sequencing of the giant panda suggests that the dietary switch could have initiated from the loss of the sole T1R1/T1R3 umami taste receptor, resulting from two frameshift mutations within the T1R1 exons. Umami taste corresponds to high levels of glutamate as found in meat, and may have thus altered the food choice of the giant panda.[70).” Furthermore, they do poorly on this diet: “However, the giant panda still has the digestive system of a carnivore, as well as carnivore-specific genes,  and thus derives little energy and little protein from consumption of bamboo. Its ability to digest cellulose is ascribed to the microbes in its gut.  Pandas are born with sterile intestines, and require bacteria obtained from their mother’s feces to digest vegetation.  The giant panda is a “highly specialized” animal with “unique adaptations”, and has lived in bamboo forests for millions of years.  The average giant panda eats as much as 9 to 14 kilograms (20 to 30 pounds) of bamboo shoots a day to compensate for the limited energy content of its diet. Ingestion of such a large quantity of material is possible because of the rapid passage of large amounts of indigestible plant material through the short, straight digestive tract.  It is also noted, however, that such rapid passage of digesta limits the potential of microbial digestion in the gastrointestinal tract,  limiting alternative forms of digestion. Given this voluminous diet, the giant panda defecates up to 40 times a day.  The limited energy input imposed on it by its diet has affected the panda’s behavior. The giant panda tends to limit its social interactions and avoids steeply sloping terrain to limit its energy expenditures. ”
Dogs simply don’t fit the odd mutation found in pandas. Dogs are carnivores, and through domestication as humans have taken them as pets, they have been subjected to what we feed them. This, however, has not changed them from carnivores to omnivores. It has simply forced them to survive on what was provided to them. Often, as humans seem fit to do, we place animals in categories that make the most sense to us at the time. We rationalize what we feed them by designating them as ‘omnivores’ or ‘omnivorous’ or ‘scavengers’. We make these terms up to fit our perception of reality. And pet food companies jump on these terms to justify the ingredients in their dog food.
There are differences in carnivores. Takes cats for example. They are ‘obligate carnivores’. Cats must have meat to survive as they need things found in meat that carbohydrates (plants) can’t provide. This includes vitamin A. They cannot convert beta carotene to a usable form. They also need taurine, which is not found in plants. Arginine, which is only found in meat, is an amino acid essential to cats. Without it, they can die!
Dogs are similar. They can convert beta carotene, however, not efficiently. Only 50% or less. Dogs must also have taurine or they can die from heart failure. Dogs must also have an animal-based form of vitamin D, known as D3, as they can’t use plant-based calcium. It is worthless to them. Additionally, dogs must get iron from animal sources. They can’t use it from plants or supplements. Additionally, dogs must have arginine from meat sources daily or they can become ill and die. Lastly, dogs cannot convert omega 3 fatty acids from plant-based oils. They must have animal-based oils which are found in fish-based oils (already converted) to be effective.
“However, in mammals, ALA is not efficiently converted to EPA and DHA. The conversion rate of ALA to EPA and DHA is believed to be <10% in humans, [19, 20] and also is believed to be rather limited in dogs [21, 22] and cats. [23, 24] Therefore, when supplementing omega-3 fatty acids, fish oil is a more potent and efficient source of EPA and DHA as compared with products rich in ALA such as flaxseed, linseed, or canola oil. Supplementation of ALA does have benefits, especially in management of dermatologic disease,  but different omega-3 fatty acids have different effects on the body and on disease.”
So yes, dogs need meat and they need it daily! There is no evidence proving dogs need carbohydrates or that they are designed to consume them or use them. In fact the National Research Council which determines what dogs need nutritionally, states dogs have no nutritional need for carbohydrates. None! What dogs need are animal proteins and fat and the amino acids, minerals and vitamins provided by them.
So really? Is there any question on whether or not dogs are carnivores? There shouldn’t be! Everything they need for nutrition is found in animal-based foods. Nothing of what they need is found in plant-based foods or carbohydrates. Their anatomy is distinct in having all the characteristics found in carnivores!
If you would like more information on how to make home-prepared meals for your dog that are nutritious and contain animal meat and protein, then my book, “Raw and Natural Nutrition for Dogs” is exactly what you need! It has easy, simple-to-follow instructions on preparing either raw meals with bones (yes, these are safe if fed raw!) or home cooked meals with minimal low-sugar carbohydrates (which are only added to help form stools). This is not difficult and your dog will appreciate you so much for it!
A great companion supplement to add to your dog’s diet is the Berte’s Immune Blend. This supplement contains animal-sourced vitamin A and D3, as well as probiotics and digestive enzymes. It is a great supplement for supporting your dog’s immune-system. Another good addition is the Berte’s EPA Fish Oil Capsules. Omega 3 fatty acids are also great for the immune system and they are renal, liver and heart protective and great for healthy skin and a glowing coat!