There are carbs and there are carbs.
I do feed my dogs raw and the best "vegetable" you could feed to a dog would be green tripe.
Would that answer your question ?
I personally have never seen a wolf or coyote go through a field of corn or other vegetables munching on them. *lol* They do, however, eat the stomach content of their prey and that's their 'vegetable'. The protein in dry dog food consists mostly of soy, not animal protein and isn't really all that good for our four legged friends. The higher quality kibble fares somewhat better in that regard but is not species appropriate either.
If you really want to feed the way nature intended you would have to feed an entire carcass, but I for one couldn't stomach that.
@Jeeves: well said ! At times where I had to feed kibble to my dogs, I ALWAYS supplemented them with digestive Enzymes. (ProZyme) to help along with a proper digestion.