what they're teaching...

Actually, dogs, like coyotes, are carnivorous, but are also opportunistic feeders, and will eat non-meat items.  That fits into the omnivore category somewhat, although they predominantly choose meat over other items.  Cats, on the other hand, are obligate carnivores.  So, I'm not sure your friend is totally wrong on that point, even though some of the other material is questionable.

I heard somewhere that Purina is donating $250,000 to animal shelters but they are spending $2.5 MILLION advertising and bragging themselves up, to let everyone know they are doing it.  Interesting, if anywhere close to the truth.
 
Most of us here, I think, would agree that Purina, Science Diet, et al, are pretty crappy foods.  Most of us would like to see vet schools do a better job of teaching animal nutrition, by removing the current bias that exists there BECAUSE the major pet food companies sponsor much of what curriculum there is.  But what is the solution to the vet school dilemma?  Who, other than pet food companies, has done the research to support writing a curriculum, no matter how biased?  Who, other than pet food companies, is going to spend the bucks?

Just remember....there is no money to be made in keeping dogs (or people) healthy

wait a minute. Humans cannot digest cellulose. Nor can cows. Only bacteria contain the enzyme that breaks cellulose apart. Cows digest plant matter by grinding it up very well with their big flat molars, then it goes down into special compartments in the stomach where it gets digested by bacteria. All herbivores and ominvores digest their food this way-- lots of chewing, lots of time spent fermenting the plant material in the gut with bacteria. Humans do this too. Dogs do not. They lack the teeth required to break the cell walls open. Food is rapidly transited through the gut, and there is no time for it to get fermented by bacteria. The only way a dog can get nutrition from plant matter is if a human grinds up the veggies or cooks them. In the wild, a dog might eat fruits, and the veggies herbivores have partially digested (stomach contents, poop. Ever noticed dogs love to eat poop?).
Dogs are NOT omnivores by design. With human help they can eat an omnivorous diet.

I agree with you Spiritdogs.  Canines are primarily carnivorous although will resort to plant material if necessary to sustain them.  A well fed dog/wolf, even when eating fresh kill will avoid the guts at all cost (ie stomach)...but WILL go straight for the liver...an excellent source of protein.  That being said...I still don't believe that an dog should NOT be fed any veggies (must be pulv. of course).  My dogs LOOOVE carrots, and I do know they don't get any nutritional value from them but its better than the alternative (rawhide etc.).  My lab even loves broccoli...which I give her very seldom... the calcium oxolates can cause bladder stones!  Yikes!  

Dogs do actually have teeth with which to grind food.  Cats do not.  Dogs are kind of between us and cats.  My dogs grind their kibble at every meal....

There is a difference between cows, aside from the size and shape of teeth. Cows have more than one stomach, humans have one stomach. While we may be better at digesting some cellulose better than a dog, it doesn't stay in a human long, either. I once had a few bowls of a high bran cereal for breakfast. An hour or so later, I knew I had made a mistake. That is, all that rough cellulose made it's way through in an hour or so. If, OTOH, I eat cornflakes, which has been ground, causing most of the cellulose to break down, I will get more nutrients as it passes through. This may be due to my high basal metabolic rate, thanks to a physical active job, dog walking, and my weightlifting schedule. Some days, my job requires climbing on scaffolding, including a 30 foot vertical free climb on an access ladder, requiring total body involvement, sometimes carrying tools and materials with me, up to 30 additional pounds, similar to a dog's normal motion. This demand increases calorie consumption.
 
Cows will chew and swallow to one stomach. Later, regurgitate and swallow to another stomach, etc. You definitely don't want to smell cow-breath.
 
According to more than one scientific source, including one that frequents i-dog, wolves go for the body cavity and rip open the stomach, amongst other things. They  will even eat some of the stomach contents in order to get at the stomach lining (tripe). Wild canids do scavenge. They do forage plant matter. The Maned Wolf of South America likes one plant in particular that the plant was named after it. Fruta Lobo, Wolf's Fruit. I would say that the gray wolf is more carnivorous in behavior than the Maned Wolf. The New Guinea Singing Dog (NGSD) is omnivorous, eating both plant matter and animal protein. It is modern prototype of what became canis lupus familiaris.
 
Let's not forget that there are 26 genetic differences between dog and wolf. That the dog has been eating what man is eating for 100,000 years. Robert K. Wayne says the differences are so subtle as to say that your dog is a domesticated wolf. Other analysts disagree with that assessment but the ASM and the Smithsonian Institute agreed to a species nomenclature change to show that the dog is descended from the Gray Wolf, which, IMHO, does not lessen the need to understand those 26 genetic differences.
 
Even the beloved Dr. Ian Billinghurst suggests BARF, which would include mashed or blended vegetable matter. And for those concerned about bone fragments, grinding the bone. Cooked or not, mashing and grinding will help to break down cellulose.
 
And my dog eats grass, like my cat used to eat grass. While there may be some nutrients, I think it is done primarily for the roughage. It helps clean the GIT, fast or not.
 
I did have a question for you Mudpuppy. If I recall, your specialty was genetics. Did you ever come up with an analysis of the 26 differences? Some of Wayne's pages do have the genetic markers to show similarities. Since I'm not an expert in genetics, I haven't tried to tackle it, though I might give it a try. He writes in a style that is fairly easy for a layman, such as myself.
 

really?which teeth are those? my dogs have sharp canines in the front, for stabbing, and molars that look kind of like sharp wedges in the back, for slicing. I see no flat grinding molars in there. Certainly they can smash fragile kibbles with those slicing teeth, but no way can they grind up a carrot into a digestible state.

Here's a nice quick site on carnivore morphology, which an nice view of the teeth of a grey wolf:
[linkhttp://www.ucmp.berkeley.edu/mammal/carnivora/carnivoramm.html]http://www.ucmp.berkeley.edu/mammal/carnivora/carnivoramm.html[/link]

Dogs jaws CANNOT move in a grinding motion (as in side-to-side).  There are not flat, meeting surfaces on the teeth (that would do the grinding).

They rip, tear, and swallow.

Dogs have a posterior recurve coronoid process. Wolves do not. A wolf's coronoid process is somewhat like a jagged triangle. The coronoid process fits into the zygomatic arch and allows the attachment of the massiter muscle group and affects how wide the jaw opens and the biting strength. Dogs do have premolars, though they are not as wide and flat as a cows. They do well for crunching and some shearing. My dog will eat grass but he doesn't care for a carrot.

Yipppeeee, the Om/Carn debate again!
 
Although dogs are taxonomically listed in the order of carnivora, they are considered omnivores in their eating habits, like bears. The modern domestic dog is NOT the same animal as their distant ancestor. We have "bred OUT" their wild characteristics and traits with all of our selective breeding.
The cecum in the "dog" does produce bacterial activity for digesting different forms of "fiber". So where some types of fiber cannot be digested, other forms of fiber can be. Fiber does serve a purpose in the diet of dogs, as Ron mentioned. If it was NOT necessary to some extent, why do so many people sing the praises of pumkin when a dog is "irregular"? The type of fiber in pumkin serves to absorb or add water in the GIT, which regulates the system.
Wild canids do consume the gut contents first. The alpha's in the pack are usually the ones that get the best stuff, which makes them more healthy than the other pack mates and also helps them to maintain their status as pack leader. The rest of the pack get's the leftovers. The contents of the "gut" contains many nutrients and beneficial bacteria (probiotics) that assist with the digestive processes and also contains the "fiber" the prey has consumed and is already somewhat predigested.
 
Some ruminant's teeth are not flat, they are ridged (I know from personal experience) and very SHARP. So, could we say that, deer for instance are carnivores because their teeth are ridged and very sharp? So where the dental structure does play a part in an animals dietary behaviors, it's not the sole determination of them. It's the entire system of digestion, starting at the mouth and ending at the anus.
 
Dogs have evolved due to human interference and domestication, but that does not change what they have become. A dog not only eats plant matter when meat is unavailable, but actually seek it out at times due to it's physical NEEDS.

I honestly cannot say that I've ever seen a dog truly chew kibble. Maybe crunch one or two bits, but never CHEW.

ORIGINAL: kennel_keeper

The cecum in the "dog" does produce bacterial activity for digesting different forms of "fiber". So where some types of fiber cannot be digested, other forms of fiber can be. Fiber does serve a purpose in the diet of dogs, as Ron mentioned. If it was NOT necessary to some extent, why do so many people sing the praises of pumkin when a dog is "irregular"? The type of fiber in pumkin serves to absorb or add water in the GIT, which regulates the system.
maintain their status as pack leader. The rest of the pack get's the leftovers. The contents of the "gut" contains many nutrients and beneficial bacteria (probiotics) that assist with the digestive processes and also contains the "fiber" the prey has consumed and
Dogs have evolved due to human interference and domestication, but that does not change what they have become. A dog not only eats plant matter when meat is unavailable, but actually seek it out at times due to it's physical NEEDS.

 
Excellent points. Even those here that feed raw or homecooked often add probiotics or look for it in their kibbles. Which would mean that they are eating what could be modeled after a kill in which stomach contents are consumed, even if it was only to get at the stomach lining.
 
I also agree that teeth do not necessarily define an animal's taxonomy. Humans have incisiors, fangs and the rest are molar type teeth, and yet we eat meat. So do some other primates. We are omni by behavior and survival. That is, being omni has led to our survival, along with the large brain, the opposable thumb, and a viciousness against which other animals pale.
 
It's nice to review all the evidence.
 
Ditch-digging science-nut,
Ron.
 

Ron,
Here is an interesting study about wolf vs. dog bite strength and devising a method to test it. I saw it and just KNEW it would be something you would enjoy. There's all kinds of formulas and such (math, ug).
 
[linkhttp://www.asee4ilin.org/conference2005papers/p170.pdf]http://www.asee4ilin.org/conference2005papers/p170.pdf[/link]