Are Dogs Carnivores — or Omnivores?

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Are dogs carnivores — or omnivores? The Great Debate goes on.
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When it comes to choosing dog food, it’s important to know the answer to that question.

So, if you’ve already been told dogs are indifferent omnivores with no natural preferences…

Or that they’re strict carnivores with an innate aversion to eating fruits and vegetables…

All scientific evidence clearly points to the fact that…

Dogs Have a Natural
and Undeniable Carnivorous Bias

From DNA studies, we know dogs evolved directly from the timber wolf somewhere around 15,000 years ago1.

And, of course, it should come as no surprise. Wolves are clearly carnivores.

So, by their very genetic pedigree, dogs also demonstrate similar and noticeable carnivorous traits. Their teeth, their digestive systems and their behavior clearly confirm this fact.

Yet dogs must also be recognized for their significant omnivorous ability. Their proven ability to digest carbohydrate-based foods has been known for many years.

After all, modern genetic research has proof that ten canine genes play key roles in starch digestion and fat metabolism.2

However, a dog still shows unmistakable evidence that its body is optimized for eating meat.

Dogs Don’t Grind — They Chop

For comparison, think about a typical herbivore — a dairy cow. Picture the way they “chew their cud”.

Cows chew widely from side-to-side. And they have broad, flat back teeth. And flat teeth are ideal for grinding grains and plant material into finer particles.

True omnivores (like humans) share this same combination of boxy back teeth and sideways grinding motion common to herbivores. Think of your own mouth and how you chew.

Dogs, on the other hand, don’t have flat teeth. Like all carnivores, they have narrow pointy back teeth.

Plus dogs can’t chew from side-to-side. Their jaws can only move in an up-and-down, chop-chop motion. It’s the perfect combination for cutting meat into smaller chunks.

No Salivary Amylase

Herbivores and omnivores possess one aid to digestion carnivores typically lack.

Carnivores do not produce amylase in their salivary glands.3

Amylase is a specialized enzyme most herbivores and omnivores produce in their saliva. It helps begin the break down of starchy carbohydrates into simple sugars — before they enter the stomach.

Although dogs do produce amylase, the enzyme is added further down the digestive tract — in the pancreas and small intestine.

Edited4

Digestive Anatomy

Since they consume fewer but larger meals, carnivores have bigger stomachs than their grazing, plant-eating counterparts.

What’s more, meat-eating animals exhibit a higher concentration of stomach acid. This allows faster digestion of animal protein.

And the stronger acid kills the disease-causing bacteria abundant in decaying meat.

What’s more, herbivores have an unusually long gastrointestinal tract — exceeding ten times the animal’s body length. Longer systems like this are needed for consuming a plant-based diet.

Welcome to the Age of Choice

Yet in spite of this natural carnivorous design, dogs have still managed to evolve over thousands of years — even surviving on the meat and non-meat scraps and leftovers of human existence.

So, over time, dogs have proven to be fully capable of thriving on a variety of foods.

Today, the dog food marketplace has become a living, breathing witness to the animal’s adaptive ability — and is abounding with an astonishing array of product designs.

Some favor meat. Some feature vegetables. And others are made almost entirely of cereal grains and beans.

So, how do you choose the right one for your pet?

The Bottom Line

Knowing that dogs are optimized for eating meat can make it easier to recognize better dog foods.

Even though dogs do demonstrate a notable omnivorous capacity, we believe it’s important to give preference to meat-based products. That’s because…

Whether you believe they’re carnivores or omnivores, dog’s possess an undeniable carnivorous bias

Meat-based dog foods are closer to a dog’s natural ancestral diet. They’re more like the real thing.

Footnotes

  1. Lindblad-Toh K, Wade CM, Mikkelsen TS, et al, “Genome sequence, comparative analysis and haplotype structure of the domestic dog”, December 2005, Nature 438 (7069): 803–19
  2. Axelsson E. et al, The genomic signature of dog domestication reveals adaptation to a starch-rich diet, Nature, 2013 Jan 23, doi: 10.1038/nature11837, Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 75237 Uppsala, Sweden
  3. Animal Health Diagnostic Center, Cornell University School of Veterinary Medicine
  4. 11/17/2014 Removed: “So, without salivary amylase, a dog’s carbohydrate digestion can be decidedly more difficult.”
  • Sarah Griffiths

    Bears have all the same carnivorous features as dogs, but they are omnivores as well… just saying. There’s no point looking at ancestry, because the dogs today are NOT wolves. They are dogs. Buy a dog food that lists meat as the first ingredient and doesn’t have a lot of processed nonsense. Additionally, I’m not sure dogs in the wild would eat grains, because grains are cultivated and don’t really grow in the wild. But veggies/fruits/tubers etc, do. It’s not that hard, really… common sense…

  • aimee

    Hi Mary,

    From your reply i can see you didn’t understand what I was saying.

    The Panda as a member of the order carnivora is a carnivore. This is the taxonomic classification of the Panda and it is how the Panda is referred to in the scientific literature.

    For example the paper Animal Physiology. Exceptional low daily energy expenditure in the bamboo-eating Giant Panda by Nie Speakman et al 2015 starts with “The carnivoran giant panda has a specialized bamboo diet to which its alimentary tract is poorly adapted”

    The panda is a carnivore that eats a plant based diet. I thought I was clear on that as I said the panda is a hypocarnivore/ primarily vegetation in regards to diet.

    The polar bear is interesting and if you look back at the diagram I posted you’ll see that color line to the polar bear is blue for mesocarnivore/ omnivore which we all recognize bears as being. The habitat of the Polar Bear though doesn’t support a lot of plants so the diet consumed is primarily flesh. So the question is did the polar bear lose the metabolic pathways that define an meocarnivore/omnivore or are they still present. Will polar bears be flexible enough to adapt to a more varied diet? They are already consuming significant amounts of vegetation in certain locations.

    The wolf eats a diet that is that of a carnivore but from the diagram I posted you’ll see all of the canids, including wolves are classifed as mesocarnivores/omnivores.

    The wolf’s range and therefore diet has been limited by human activity. It has been proposed (Bradshaw 2006) that the diet would be more varied if the constraints didn’t exist.

    In regards to teeth here is a description from Millers Anatomy of the Dog by Evans and Christensen “the upper molar teeth are irregularly flattened…. ” Here is another description from Veterinary Dentistry Basics the molars are described as having “flat occlusal tables” and here’s a lay description from someones blog “What are the molars used for? We can get a clue form these teeths flat surfaces” http://www.dailydogdiscoveries.com/tag/function-of-dogs-canine-teeth/

    I’ll post a pic showing classification as teeth suited for plant and animal matter and one showing that the shape of the lower first molar is consistent with a mescarnivore/omnivore.clasification

    And of course feral dogs eat plant matter “Feral dogs may feed on fruit crops including melons berries grapes and native fruits such as persimmons and blackberries” http://icwdm.org/handbook/carnivor/FeralDog.asp

    I outlined the nutritional differences between dogs and cats. Cats require nutrients that dogs can synthesis from plant based precursors.

    From The Nutrition of the Domestic Cat a Mammalian Carnivore by Macdonald, Rogers and Morris

    “This evolutionary development has resulted in more stringent nutritional requirements for cats then for omnivores such as the rat, dog and man”

    I understand that you can not accept that dogs based on their anatomy
    and physiology are classified as amesocarnivore/omnivores because it
    goes against your belief system but you did ask for people to look at
    the anatomy and physiology of the dog and cat. : )

    http://uploads.disquscdn.com/images/eb16deae346e59e19e6b989e2a2f923054ae052f383e07fdfff2ea1b8cb473bb.jpg
    http://uploads.disquscdn.com/images/a20bf7b62e22396894e90717e0796ae81ab69b0eedfcb5a284b0707ec3993d4b.png

  • aimee

    Hi Mary,

    You challenged readers to “please study the anatomy & physiology of not only
    domestic canines & felines but of their true wild ancestors, wolves
    & Wild Cat, and they are still classified as a true carnivore(cats
    are actually obligate carnivores)”

    Both dogs and cats are members of the order Carnivora so yes in that sense they are carnivores. In regards to diet there is a lot of variety within the order, there are the those members who eat primarily flesh who are classified as hypercarnivores and then there is the Panda who consumes primarily vegetation and is classified as a hypocarnivore. Many members of the order Carnivora are classified as mesocarnivore which falls between these two If you use the terms carnivore, omnivore and herbivore, hypercarnivore would be considered carnivores, mesocarnivore would be equivalent to omnivore and hypocarnivore could be considered equivalent to herbivores.

    The systemalists, that branch of science that studies anatomy and physiology and classifies flora and fauna has classified cats as hypercarnivores whereas dogs are classified as mesocarnivores. In other words cats are carnivores and dogs are omnivores.

    To understand why dogs are mesocarnivores ie omnivores you need to look at the anatomy and physiology of the dog.

    Take the dentition for example. The dental pattern of the dog is non specialized. The dog has well developed incisors useful for nipping plant material as opposed to the incisors of the hypercarnivore cat which are teeny tiny. Both the cat and dog have teeth for piercing and shearing flesh, canines,and premolars, but dogs have flattened molars for grinding something not seen in the cat. Both cusps of lower molar of the cat are sharp and pointy but in the dog a different pattern is seen, one cusp is point ant the other is flattened. This is the pattern of a mesocarnivore/omnivore

    The taste receptors in the tongue also align with an omnivorous diet. Dogs mesocarnivore/omnivore can detect both salt and sweet. Cats, hypercarnivore/carnivores, can detect neither. Salt is necessary for life, hypercarnivores meet their need via the high consumption of tissue. Animals that don’t eat primarily flesh need to seek salt out, salt receptors allow for this.

    Sweet receptors allow an animal to choose vegetation that is safe to eat, For a hypercarnivores/carnivore whose diet includes very little plant material sweet receptors are of no benefit to animal and are lacking in this category of animals.

    Other reasons dogs are considered omnivores are that they can synthesize Vit A, and arachidonic acid
    from plant based precursors, they have metabolic pathways in the liver for detoxification seen in plant eating animals. Plant eaters are more likely to ingest toxins. Cats, and other carnivores lack the pathway.

    Another characteristic of omnivores is that they can down regulate protein need. Dogs are capable of doing this whereas cats do not do this to any significant degree.

    For these reasons and others dogs are classified as mesocarnivores/omnivores. But dogs do require dietary Vit D… which is why it is sometimes said that they are omnivores with a carnivore bias.
    http://uploads.disquscdn.com/images/e44f5f41d6a5d4f6fe10e479742a371581402e7970f5c7398bfdd8aa9cb4621e.png

  • Mary

    Oh God really, yes wolves freaken eat grass – would you people please study the anatomy & physiology of not only domestic canines & felines but of their true wild ancestors, wolves & Wild Cat, and they are still classified as a true carnivore(cats are actually obligate carnivores) – when you are feeding complete raw diets, their protein % is higher and that 20% protein you mention sounds more based on dry kibble(even most canned foods have more protein than most dry kibbles – not all ) And some medium to large breed dogs living to their late teens fed a dry kibble is because they were never over vaccinated; never fed toxic poisons of Heartworm pills; no chemical flea tick & mosquito products; no over use of antibiotics/steroids/NSAID’s but it is still RARE that they live that long being fed even the so called best dry kibble or canned foods on the market

    Again on a complete raw diet primarily made from herbivore animals, not poultry pork not even tons of fish, and of course, none of the rest of the garbage being done to them as stated above of you should never over vaccinate not even rabies! no HW toxic poisonous pills, etc etc

    Small breed dogs & cats normal life spans are mid 20’s(many have lived to late 20’s – my own neighbors cat lived to 30yrs as he was always fed complete raw diet and NEVER vaccinated ever)

    Medium to Large breeds is late teens (many medium breeds have actually lived to early 20’s) and I have too many to mention on large breeds that lived to 18 & 19yrs old and were only vaccinated 1x including rabies and others were never vaccinated ever, and always fed a complete raw diet

    X-large breeds is early to mid-teens; Again I have too many to post as to living to mid teens that were Great Danes & Mastiffs……just talked to friend back in April 2017 that is professional breeder of Great Danes for over 30yrs now, always fed complete raw diets, only vaccinated 1x and not these freaken MUMBO JUMBO Combo vaccines either – just parvo & distemper and he just lost one of his retired stud dogs back in March at 15yrs old and all of his dogs live to mid teens

  • Mary

    Yes, dogs, wolves(who are the true ancestors to domestic dogs not coyotes) do eat grasses, dandelions, even some herbs whether for medicinal purposes or not. They are still, last I check LOL, (check out their anatomy they are CARNIVORES!!!) TRUE Carnivores! They do NOT eat vegetables and even wolves will eat 2% of their diet of fruits – usually seasonal berries but have been observed eating apples, pears as well and one wolf has been observed eating watermelon—again they are still true carnivores they are NOT omnivores. And when they eat grass many times(not always) it is to purge something bad that they ate including dogs. They also eat grasses to get little nutrients from grass(their digestive system is so fast that they do not get much nutrients from plant matter in the first place) and for dogs, many times their digestive acids are out of wack due to the garbage people feed(commercial dry kibble & most canned foods) but even when fed complete raw diets, sometimes(just like humans) their stomachs, especially if somebody like allopathic vets “over use” antibiotics! so their systems need some probiotics added back to their diet for a short period of time.

    And you can leave your smart butt comment about God….sounds like you are an atheist and when your time comes, well you’ll be asking for God to forgive you for all the sins you committed and didn’t repent them in your life here on Earth.

  • Vance Tullier

    I’ve personally seen dogs, coyotes, and wolves all eat grass. Last I checked that rather defies the concept of a pure carnivore and aligns itself quite well with the original article in favor of the carnivorous slant.

    Personally I choose to feed a much higher protein level diet for that reason but I’d be lying if I didn’t agree that I’ve seen dogs living into their late teens on ~20% protein diets that thrived in apparent health their entire lives without excessive visits to the vet.

    That said, the “Because God!” actually made me laugh a bit in a murky morning so thank you for that. 🙂

  • Mary

    LOL

  • Emma Bolderson

    Only humans created humans. God plays no part in what we do, nor does he want to.

  • Mary

    God created wild dogs/feral dogs and humans domesticated them and then created many different breeds but again, God created them because if He didn’t want them by mixing breeds and creating new breeds, they still wouldn’t be around. Just like God created all wild life, and human beings as well

  • Emma Bolderson

    God didn’t create them, humans did

  • coolmtnman

    the taurine in grocery store cat food has synthetic taurine added because the taurine is lost in the processing

  • coolmtnman

    plant eating mammals and carnivores evolved together. A true carnivore thins out the weak ,diseased, old and overpopulated. Dogs are not true carnivores and the healthiest dogs I’ve ever seen were fed a good quality plant diet. Cooked food doesn’t need to be chewed.

  • nickrin

    They were fed whatever was left over. The practice of feeding entrails was abandoned because of hydatid disease (Echinococcosis).

  • coolmtnman

    pre dogfood dogs were never fed meat but only bones and entrails

  • coolmtnman

    I’ve seen several well fed vegan dogs and they are healthier than any non-vegan dogs I’ve ever seen

  • coolmtnman

    Pre- dogfood dogs have never been fed meat but mainly the bones and entrails and whatever plant food the owners fed them.

  • Bela Animal Legal Defense

    That cat needs taurine and you are going to harm your cats heart and liver function by doing this as this is an undiputsble fact.

  • Bela Animal Legal Defense

    While it is true about the primary enzymes, the plant protein in vegan dog food is already “broken down” and much more digestible. they do have the ability to absorb plant protein and have amalayse in their pancreas. It’s an interesting discussion bc both sides have very valid points when you get past the insults lol.

  • Johnny M

    How about this review of 4 separate studies of vegetarian diets in dogs that concludes “a significant and growing body of population studies and case reports have indicated that cats and dogs maintained on vegetarian diets may be healthy – including those exercising at the highest levels – and, indeed, may experience a range of health benefits.”

    https://www.ncbi.nlm.nih.gov/pubmed/27657139

  • Johnny M

    Sorry, what science is inescapable? The science that says “A significant and growing body of population studies and case reports have indicated that cats and dogs maintained on vegetarian diets may be healthy – including those exercising at the highest levels-and, indeed, may experience a range of health benefits.”?

    https://www.ncbi.nlm.nih.gov/pubmed/27657139

  • Mary

    So because you people might actually believe dogs are omnivores when they are “Not” God created them(and if you are a non-believer, then Mother Nature) as CARNIVORES. Just because the last 80+ years the PFI & allopathic vets have brain washed you into believing dogs can “survive” on GARBAGE dry kibble & most canned foods including plant matter/veggies, or that raw fed dogs (& cats) can eat vegetables and some will “survive” but not most, doesn’t mean you turn a carnivore into a vegan!! That is cruel. And surviving on grains, carbs is all BS from the PFI. Our dogs & cats are getting sicker & sicker at younger ages(over vaccines also account for this along with toxic poisonous HW pills and chemical flea tick & mosquito products) & they are dying younger as well.
    Before the PFI industry became larger in the late 1950’s, even farm dogs who were fed scraps of meats/fats/organ meats mainly liver, lived LONG vital & healthy lives, they weren’t vaccinated either or given these other toxic drugs.
    What people tend to not even realize or know, is that the “normal” life span of dogs & cats BEFORE the PFI became involved being fed complete raw diets, not over vaccinated(shit they were rarely vaccinated at all) and now PFI adding all these veggies into the diet(even some pre-made raws are being made incorrectly with adding veggies to their products when vegetables actually “over work the pancreas to produce more enzymes to break down all the cell walls, carbs etc”
    Small breed dogs & cats normal life span was & still is when fed complete raw diets primarily from herbivore/ungulate animals and not over vaccinated, not fed toxic HW pills, etc:
    mid 20’s! Many have made it to late 20’s. Heck even my own neighbors cat was NEVER vaccinated and fed complete raw diet its whole life and lived to 30yrs old!!!
    Medium to large breeds is actually late teens(some medium breeds have lived to early 20’s) I have friends that have had large breed dogs live until they were 19yrs old totally vital & healthy, never saw a vet, only vaccinated 1x including rabies,(some had their dogs spayed/neutered but allowed the dog to grow to full growth at least 2yrs before spay/neuter) and only time was ever ill was the last week of their lives when they were dying(some allowed the dogs to pass at their home in loving environment)
    X-large breeds is actually early to mid teens. I not only have friends with X-Large breeds, I also know Natural Rearing breeders, and my friends have more friends and know more NRB of these large breeds—they have lost Mastiffs & Great Danes at 15yrs & 14yrs!! and still have several alive and doing unbelievably well at 14yrs & 13yrs—they were weaned onto complete raw diets as puppies and NEVER vaccinated ever. I don’t know about you but I grew up around Great Danes, and although very well loved, nicely taken care of, several actually grew up on Cape Cod with tons of daily exercise on the beach, but were fed garbage dry kibble & canned foods(some were over vaccinated as well) and they never made it beyond 9yrs old(most were only 8yrs)
    So just because a dog can “survive” on grains, carbs, “starches” which many veggies are starch veggies that all turn to sugars, doesn’t mean they live long “vital & healthy” normal life span lives. And yes, I’ve seen some posts below on how the oldest vegan dog lived til 28yrs old. Never says how many times that dog was at the vet because it was “sick” I”ve seen many dogs & cats, even kittens & puppies, that their vegan & vegetarian owners were turning “carnivores” into the same life style they choose to live, and they ended up at deaths door at the ER’s, and although given IV fluids, the vets even didn’t pursue and drugs(thank God!) and fed them complete raw diets and most of them fully recovered because they were not getting the nutrients necessary for their “carnivore” bodies!

  • Mary

    Dogs are NOT omnivores they are carnivores, true carnivores. It is how their bodies are designed. Go and study the anatomy & physiology of canines and felines and then show me where they are omnivores.
    It is a very RARE case that a dog would live that long and I also wonder how many times it was at the vet’s office. I’ve seen “vegetarian/& vegan” fed dogs & cats, end up at the ER because they were so depleted of protein/nutrients they require in their bodies from lean muscle meat/fat/organ meats including liver! and the vets instead of just giving them IV fluids, or even any “drugs” they actually started to feed them raw meat diets, and that was all it took to totally improve their “poor” health from being fed a damn vegan/vegetarian diet.
    Listen I was a vegetarian for many many years because I love all animals so very much, but I did NOT turn my dogs & cats into vegetarians because they are true carnivores(cats are actually obligate carnivores)
    So yes, for people that are doing this to their dogs &/or cats, that is actual animal cruelty and they don’t deserve to have an animal. I wouldn’t bring it to a shelter because they will be fed GARBAGE dry kibble & most canned foods are GARBAGE as well, but I”d find a good rescue or a nice loving family that would feed a species appropriate complete raw food diet

  • Mary

    Exactly. I’m so tired of vegans and vegetarians turning their CARNIVORES into vegans or vegetarians. They will NOT live normal vital & healthy LONG lives. She doesn’t deserve to own a dog or cat when they decide to do this to them. Sure there will be some dogs & cats that will “survive” but they won’t “thrive”

  • SeatanMan

    Deposit the animals at an animal shelter, that are looked after and cared for just because you don’t believe in their diet? Yes, let’s inundate shelters with more animals because you don’t believe in what they’re being fed. The oldest living vegan dog lived to 28 years old, and because dogs are omnivorous, they can thrive on meat-free diets. In fact, some dogs are ALLERGIC to meat and are forced to become vegetarians. It is much better to give a diet consisting of fresh foods, pulses etc, than kibble, which at best may have 5% of poor-quality meat, which has been cooked at temperatures up to 1000 c, taking away any nutritional properties.

  • Silas

    Just a quick note: Both of the responses to this comment seem to think that the comment originator (Madeline Cohn) is herself saying that she is vegan and makes her dog/cat eat the same way. Even if we eschew our reading skills and ignore the rest of the comment (as appears to have been done), surely you realize that there’s no such thing as a dog/cat, right? It’s one or the other, not some monstrous thing that requires a slash. Thus it must be merely an example.

    Communication, people! It’s important.

  • Penny Cleven

    I’m sorry, but this is animal abuse. feeding a cat a vegan diet goes against their biological needs. Your cat may be healthy now and it may take a couple of years for the results of this diet to make themselves known but that day will come. I have one cat that kills and consume mice(she lives indoors) we have an old house so the rodents get in. the other cat doesn’t have much interest in hunting…. they both started on regular kibble as kittens, two years ago we switched to raw and haven’t looked back… diet influences behavior, on kibble my older cat was very grumpy, depressed and 4 pounds overweight…. plant based diets may be fortified with the things a nutrient profile says they need, but form is just as important as quality and plants based foods do not provide readily available nutrients that the body can use… If you want to be a vegan have at it, if you want to share your life with a cat or a dog please understand MEAT must be part of their diet. Otherwise get a rabbit or other herbivore for a pet.