"Should it be?" is much more contested.
The reality is, a high-quality vegan dog food (or very carefully planned homemade food) can provide all the nutrients that Fido needs. Many dogs thrive on such diets.
Still, many folks argue that it's not natural.
Sure, wild dogs most assuredly consume other animals. But here's the rub. It's hard to use the "natural" argument, as if we're still raising wolves in our home.
Is the fluffy bed, water cooler, curling up for tv time, or daily walks on a leash "natural" by wild dog standards?
What about the fact that the "meat" most dogs are now consuming aren't wild animals they've hunted, but instead, scraps and byproducts from the slaughterhouse floor and reject pile? Is that really 'better' for our pets?
So, let's just let go of the 'natural' argument on this one.
More important is the health of your pet, and if you can have that correlate with your ethics. If your canine companion can fill their nutritional needs without the slaughter of other animals, is there really a reason to not try it?
Let me be clear here. I understand people are nervous about experimenting with their pets. I know we absolutely consider our animals family, and I wouldn't want to do anything to harm their health. So please, do research, talk to your vet, etc. But just as your standard MD has no real education in nutrition, the concept of a vegan diet will likely seem a little 'out there' to your local vet.
So, if all else fails, keep in mind that it doesn't have to be all or nothing. You can easily reduce your use of animal goods by splitting your dog food/treats. Mix your dogs old food, and a new vegan food, half and half (or whatever fraction you're comfortable with). You can do this gradually and see how your dog responds.
What I can tell you is that our beagle/coonhound mix, at about 2 years of age, actually preferred V-dog over her organic meat food when the first bag arrived. And she's now four years old, and her health is still great.
So, what do you think? Would you give an option like V-dog, with easy-to-read ingredients such as peas, brown rice, and potatoes, a whirl?