I love the idea of feeding my 3 dogs and 4 cats a vegan diet, but, as much as I love it for me and my daughters, I know that our bodies are built for this type of diet, but, I also am skeptical about feeding my animals that way. I'm quoting below from a study on Mammology;
"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. 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)."
That was just part of the article found at http://rawfed.com/myths/omnivores.html.