The Great Debate

[kyliegirl]

cats eat grass now and then, that is plant matter, it does not mean they are omnivores..

camels, sheep, cows, hippos are all herbivores and will eat their own kind or meat at one stage or another but it does not mean they are omnivores. their first preferance is plants.

dogs, dingoes, wolves, African wild dogs all hunt prey and eat meat but will also eat some plant matter much like cats do but in larger quantities, this doesn't make them omnivores. Their first preference is meat.

all wild and domestic cats are hypercarnivores also known as an obligate carnivore, while they can eat plant matter their system will not take anything beneficial from it and is solely build for meat. they usually eat plants as an emetic.

an omnivore is something who will eat both meat and veg and do not take preference in either. humans, pigs, chickens and some species of bears are all omnivores.

detrivores are animals that eat decomposing matter like dung, rotting foliage. such animals are dung beetles and millepede's.

insectivores are solely insect consuming species like spiders and praying mantises, echidnas.

[espinay2]

Carnivores who eat plant matter are omnivores.

I used to have a horse years ago that liked sausage sandwiches. And until a few years ago it was common to feed sheep/cattle meat meal (it was banned because of BSE/mad cow). Does these animals eating this meat make them omnivores too? My cats also love the odd piece of veggie or fruit (particularly the raisins in fruit buns!) and will munch on grass. Are they omnivores because they eat this plant matter?

Yes, I believe dogs are carnivores. Doesn't stop me giving them a few veggies occasionally too though as they are also very opportunistic ('opportunistic carnivores' if you like). The reason the species has survived so well alongside humans.

[kermat]

I believe dogs are carnivores but I feed my boys a balanced diet of mostly meat, but with some veggies and grains. They LOVE eating grass though, the longer and the greener the better - I think its an old wives tale that dogs eat grass to make themselves sick when they feel unwell because my boys have never thrown up after eating it, they love it they're like little furry 4-legged lawnmowers!!

[sas]

I believe they are not solely carnivores. Dante is on 50% meat & 50% veggies, I haven't seen him in better condition since the diet change, he has no problem with his diet and chomps it down without a thought.

I don't feed any grains or other fillers.

Edited May 9, 2008 by sas

[Danielle]

Everybody makes a great point on this thread, but as the matter stands they are scientifically classified as carnivores, so it really doesnt matter what we believe, the fact is they are carnivores.

[Guest Splodge]

I reckon dogs are carnivores.

[sas]

Everybody makes a great point on this thread, but as the matter stands they are scientifically classified as carnivores, so it really doesnt matter what we believe, the fact is they are carnivores.

What may come into play is domestication and what part that plays in the evolution of the dog.

[Elkie1]

Don't know if anyone has posted this yet but I found this on the internet.

Myth: DOGS ARE OMNIVORES.

This is false. Dogs are carnivores, not omnivores. Dogs ARE very adaptable, but just because they can survive on an omnivorous diet does not mean it is the best diet for them. The assumption that dogs are natural omnivores remains to be proven, whereas the truth about dogs being natural carnivores is very well-supported by the evidence available to us.

1.) Dentition

Look into your dog or cat's mouth. Those huge impressive teeth (or tiny needle sharp teeth) are designed for grabbing, ripping, tearing, shredding, and shearing meat (Feldhamer, G.A. 1999. Mammology: Adaptation, Diversity, and Ecology. McGraw-Hill. pg 258.). They are not equipped with large flat molars for grinding up plant matter. Their molars are pointed and situated in a scissors bite (along with the rest of their teeth) that powerfully disposes of meat, bone, and hide. Carnivores are equipped with a peculiar set of teeth that includes the presence of carnassial teeth: the fourth upper premolar and first lower molar.

Contrast this with your own teeth or the teeth of a black bear. A black bear is a true omnivore, as are we. We have nice, large, flat molars that can grind up veggies. Black bears, while having impressive canine teeth, also have large flat molars in the back of their mouth to assist in grinding up plant matter. Dogs and most canids lack these kinds of molars. Why? Because they don't eat plant matter. Teeth are highly specialized and are structured specifically for the diet the animal eats, and the difference between a bear's teeth and a dog's teeth (both species are in Order Carnivora) demonstrates how this can be (Feldhamer, G.A. 1999. Mammology: Adaptation, Diversity, and Ecology. McGraw-Hill. pgs 260.). To see a visual comparison of the teeth of a dog to the teeth of a black bear, please click here. One can logically ask: If a dog (or cat or ferret) has the dentition of a carnivorous animal, why do we feed it pelleted, grain-based food?

2.) Musculature and external anatomy

Dogs (and cats) are equipped with powerful jaw muscles and neck muscles that assist in pulling down prey and chewing meat, bone, and hide. Their jaws hinge open widely, allowing them to gulp large chunks of meat and bone. Their skulls are heavy, and are shaped to prevent lateral movement of the lower jaw when captured prey struggles (the mandibular fossa is deep and C-shaped); this shape permits only an up-and-down crushing motion, whereas herbivores and omnivores have flatter mandibular fossa that allows for the lateral motion necessary to grind plant matter (Feldhamer, G.A. 1999. Mammology: Adaptation, Diversity, and Ecology. McGraw-Hill. pgs 258-259.). Consider this quote from the previously-cited Mammology text:

"Canids, felids, and mustelids subsist mainly on freshly killed prey. These families show correspondingly greater development in 'tooth and claw'; they also have greater carnassial development and cursorial locomotion." (pg 260)

This translates to a simple fact: everything about a dog or cat's body design says they were designed for a carnivorous, hunting lifestyle geared toward killing prey. However, humans have done some major tinkering with this body design (resulting in varying sizes and conformations), but we have done nothing to change the internal anatomy and physiology of our carnivorous canines.

3.) Internal anatomy and physiology

Dogs and cats have the internal anatomy and physiology of a carnivore (Feldhamer, G.A. 1999. Mammology: Adaptation, Diversity, and Ecology. McGraw-Hill. pg 260.). They have a highly elastic stomach designed to hold large quantities of meat, bone, organs, and hide. Their stomachs are simple, with an undeveloped caecum (Feldhamer, G.A. 1999. Mammology: Adaptation, Diversity, and Ecology. McGraw-Hill. pg 260.). They have a relatively short foregut and a short, smooth, unsacculated colon. This means food passes through quickly. Vegetable and plant matter, however, needs time to sit and ferment. This equates to longer, sacculated colons, larger and longer small intestines, and occasionally the presence of a caecum. Dogs have none of these, but have the shorter foregut and hindgut consistent with carnivorous animals. This explains why plant matter comes out the same way it came in; there was no time for it to be broken down and digested (among other things). People know this; this is why they tell you that vegetables and grains have to be preprocessed for your dog to get anything out of them. But even then, feeding vegetables and grains to a carnivorous animal is a questionable practice.

Dogs do not normally produce the necessary enzymes in their saliva (amylase, for example) to start the break-down of carbohydrates and starches; amylase in saliva is something omnivorous and herbivorous animals possess, but not carnivorous animals. This places the burden entirely on the pancreas, forcing it to produce large amounts of amylase to deal with the starch, cellulose, and carbohydrates in plant matter. Thus, feeding dogs as though they were omnivores taxes the pancreas and places extra strain on it, as it must work harder for the dog to digest the starchy, carbohydrate-filled food instead of just producing normal amounts of the enzymes needed to digest proteins and fats (which, when fed raw, begin to "self-digest" when the cells are crushed through chewing and tearing and their enzymes are released).

Nor do dogs have the kinds of friendly bacteria that break down cellulose and starch for them. As a result, most of the nutrients contained in plant matter—even preprocessed plant matter—are unavailable to dogs. This is why dog food manufacturers have to add such high amounts of synthetic vitamins and minerals (the fact that cooking destroys all the vitamins and minerals and thus creates the need for supplementation aside) to their dog foods. If a dog can only digest 40-60% of its grain-based food, then it will only be receiving 40-60% (ideally!) of the vitamins and minerals it needs. To compensate for this, the manufacturer must add a higher concentration of vitamins and minerals than the dog actually needs.

Is the dog an omnivore? Its dentition, internal and external anatomy, and physiology say it is not. Even its evolutionary history (discussed later) says the dog is a carnivore. So when people tell you the dog is an omnivore, ask: "What about this animal makes you think it is an omnivore?" Make them explain their position to you before you explain yours. Chances are they'll cite this next myth as "proof".

There is more at this website http://rawfed.com/myths/omnivores.html

[Danielle]

Everybody makes a great point on this thread, but as the matter stands they are scientifically classified as carnivores, so it really doesnt matter what we believe, the fact is they are carnivores.

What may come into play is domestication and what part that plays in the evolution of the dog.

I was actually wondering about that! What are your thoughts on that sas?

I think you are right, I think domestication has a lot to do with the evolution of the dog. For example (bit off topic, but still animal related) in regards to Rainbow Lorikeets, I know you arent supposed to feed them seed (it damages the hairs on the tongue) but if you do provide it, they will eat it. But if you look at a lorry in the wild they wont go near it.....they tend to stick to the nectar bearing flowers and wont touch the seed.

This is a very interesting point and Id like to hear other peoples opinion on it.

[Guest Tess32]

What physiological changes could there have been? I don't think individual eating habits really says much about a whole species? There are plenty of vegeterian humans but it doesn't make us herbivores as a species.

Even if dogs are partial to some vegetation because they are natural scavengers, to me it's irrelevant. Unless a dog is suffering severe allergies to meat, they should be given meat based diets. Their teeth and their jaws and their stomachs are all built to consume animal parts like any other similar predator. The majority of standard, healthy dogs would thrive on natural diets because they *are* carnivores and ripping and tearing meat is an intrinsic part of their makeup as a species.

[Danielle]

What physiological changes could there have been? I don't think individual eating habits really says much about a whole species? There are plenty of vegeterian humans but it doesn't make us herbivores as a species.

Even if dogs are partial to some vegetation because they are natural scavengers, to me it's irrelevant. Unless a dog is suffering severe allergies to meat, they should be given meat based diets. Their teeth and their jaws and their stomachs are all built to consume animal parts like any other similar predator. The majority of standard, healthy dogs would thrive on natural diets because they *are* carnivores and ripping and tearing meat is an intrinsic part of their makeup as a species.

True.

I got talking to my hubby bout this last night and we came up with some interesting ideas.

Maybe dogs were once Obligate like cats. Cats can still afford to be obligate carnivores because if you only provide veges to your cat, it will leave the yard and go kill something to eat. Cats can afford to choose what their meal is, and I think that because it is harder to confine a cat, a cat still has choices - a cat still retains a lot of that wild instinct.

Dogs dont have that choice and cant afford to ignore their provided meal. Through thousands of years of evolution, a dog has become totally dependant on man and "maybe" we have adjusted their eating habits. Its not like a dog can scale its six foot fence and go kill to eat meat, they dont have the same choices as cats.

Im not sure how true this is, it was just some ideas we came up with, but what Id really like to know is "Are wolves Obligate carnivores or not?" That may have some bearing if we humans had anything to do with the dogs current dietry habits.... I might google it to see.

[Jessca]

i was watching a show called animals matter on Aurora, and they believe all dogs are vegan and to feed a dog meat is wrong and cruel, and that dogs are meant to be vegan, they prefer to eat vegies. hmmm cause im sure my dog will choose grass over his chicken frames and Barf diet any day

[Guest Tess32]

What physiological changes could there have been? I don't think individual eating habits really says much about a whole species? There are plenty of vegeterian humans but it doesn't make us herbivores as a species.

Even if dogs are partial to some vegetation because they are natural scavengers, to me it's irrelevant. Unless a dog is suffering severe allergies to meat, they should be given meat based diets. Their teeth and their jaws and their stomachs are all built to consume animal parts like any other similar predator. The majority of standard, healthy dogs would thrive on natural diets because they *are* carnivores and ripping and tearing meat is an intrinsic part of their makeup as a species.

True.

I got talking to my hubby bout this last night and we came up with some interesting ideas.

Maybe dogs were once Obligate like cats. Cats can still afford to be obligate carnivores because if you only provide veges to your cat, it will leave the yard and go kill something to eat. Cats can afford to choose what their meal is, and I think that because it is harder to confine a cat, a cat still has choices - a cat still retains a lot of that wild instinct.

Dogs dont have that choice and cant afford to ignore their provided meal. Through thousands of years of evolution, a dog has become totally dependant on man and "maybe" we have adjusted their eating habits. Its not like a dog can scale its six foot fence and go kill to eat meat, they dont have the same choices as cats.

Im not sure how true this is, it was just some ideas we came up with, but what Id really like to know is "Are wolves Obligate carnivores or not?" That may have some bearing if we humans had anything to do with the dogs current dietry habits.... I might google it to see.

Wolves aren't obligate carnivores AFIAK.

But what I don't get is about taurine...I thought cats were obligate carnivores because plant protein does not contain taurine, and cats cannot process their own?

[Danielle]

Wolves aren't obligate carnivores AFIAK.

But what I don't get is about taurine...I thought cats were obligate carnivores because plant protein does not contain taurine, and cats cannot process their own?

Hmmmm, not sure, that is an interesting point also. Let me know if you find out more....

[Just Midol]

I thought obligate just meant they get no benefit from veges. Shows how much I paid attention in science

[The Spotted Devil]

Cats are obligate carnivores for a number of reasons:

* They have a higher requirement for protein as they can't conserve nitrogen (which is why protein malnutrition can occur more quickly in the cat).

* They have a specific requirement for the amino acids taurine, arginine, methionine and cysteine. They don't have the ability to synthesise these. Taurine is only found in animal-sourced proteins. Dogs can synthesise arginine from ornithine or citrulline and cats can't.

* Cats do not have sweet-taste receptors and no salivary amylase (which initiates carbohydrate digestion). They have low activities of intestinal and pancreatic amylase etc. Dogs have higher levels of intestinal amylase.

There are so many more reasons but I don't have the time!

I had a chat with another lecturer today - his belief is that dogs are certainly omnivores but he would prefer to call them carnivorous omnivores to indicate the extent to which meat plays a part in diet. But functionally, they share more characteristics with omnivorous bears. He also pointed out that the first part of the animal that the wild dog eats is the intestines and stomach contents....then the meat! It's also worth remembering that the Order: Carnivora also includes the panda, which is vegetarian.

Edited May 12, 2008 by The Spotted Devil

[Guest Tess32]

I had a chat with another lecturer today - his belief is that dogs are certainly omnivores but he would prefer to call them carnivorous omnivores to indicate the extent to which meat plays a part in diet. But functionally, they share more characteristics with omnivorous bears. He also pointed out that the first part of the animal that the wild dog eats is the intestines and stomach contents....then the meat! It's also worth remembering that the Order: Carnivora also includes the panda, which is vegetarian.

That's interesting, the research from Mech suggested the opposite about wolves, that they shake out the stomach contents of larger prey....?

""Wolves usually tear into the body cavity of large prey and...consume the larger internal organs, such as lungs, heart, and liver. The large rumen [, which is one of the main stomach chambers in large ruminant herbivores,]...is usually punctured during removal and its contents spilled. The vegetation in the intestinal tract is of no interest to the wolves, but the stomach lining and intestinal wall are consumed, and their contents further strewn about the kill site." (pg.123, emphasis added)

"To grow and maintain their own bodies, wolves need to ingest all the major parts of their herbivorous prey, except the plants in the digestive system." (pg.124, )."

[persephone]

first part of the animal that the wild dog eats is the intestines and stomach contents....then the meat

be interesting to see what 'wild dogs' these are ...

sheep around here killed by dingoes/feral dogs usually have intestine/stomach left intact.

heart/liver/kidneys tongue, testicles are prized... then other muscle meat is eaten..

Foxes may drag the semi-dried guts around, and chew on it..but the matter it contains is usually scattered ..not consumed.

Many years ago when we were feeding our dogs sheep innards.. to try and get them eating the stomach was almost impossible . they wouldn't go near it.

[Cavandra]

Everybody makes a great point on this thread, but as the matter stands they are scientifically classified as carnivores, so it really doesnt matter what we believe, the fact is they are carnivores.

Exactly!

[Cavandra]

first part of the animal that the wild dog eats is the intestines and stomach contents....then the meat

be interesting to see what 'wild dogs' these are ...

sheep around here killed by dingoes/feral dogs usually have intestine/stomach left intact.

heart/liver/kidneys tongue, testicles are prized... then other muscle meat is eaten..

Foxes may drag the semi-dried guts around, and chew on it..but the matter it contains is usually scattered ..not consumed.

Many years ago when we were feeding our dogs sheep innards.. to try and get them eating the stomach was almost impossible . they wouldn't go near it.

Thats right Persephone...........Wild dogs do not eat the stomach if they can help it, that is true, yet a few people write books saying they do, I would say they "presume" them to eat it, but the fact is they do not.........