We feed our cats regular cat food. Partly because we have 4 and they eat a lot so we can't afford special food. I also lean towards the fact that they have pointy teeth like a lion, which is a natural carnivore.
humans have never had pointy teeth which I think makes us natural herbivores.
It is just my thought on it though. I think the most important thing is that we give our animals a loving home. :)
I don't feel comfortable giving my cats vegan food, but my calico does have an addiction to greens and they both have a taste for nutritional yeast! I stick to natural cat foods. The cheapest around is 365 dry food, but there are many others. I recently (slowly) switched mine to Natural Life. http://www.nlpp.com/default.htm
Please don't let your cats hunt outside! Vegan or non-vegan food inside, there are pros and cons to each and personally I have one mostly vegan cat and one meat-eater, because these are the foods they've individually done the best on. I know it seems natural to let your cat hunt outside, but not only are they unnatural predators in these environments, killing and/or maiming birds and small mammals, this is also an excellent way to spread disease. Also, the lifespan of an indoor cat is usually more than double that of an outdoor cat, and the ways the outdoor cats die are not usually "natural" in any way (often hit by cars). I know some people consider it cruel to keep their cats "confined" indoors, but my cats are happy and content, as are all housecats who've always been kept indoors (I know cats who have previously spent a lot of time outdoors will often want to continue to go outside - that's another story).
I know this is old, but I completely agree with nic. One of my cat's was attacked outside by our next door neighbors dogs and she didn't survive, and it's made it to where I won't let her sister out or the two boy cats we have now. Although, I think if you even tried with these cats, they wouldn't budge to go outside. When the door opens, they run away from it and I make the indoors as much as a place to play and get all the activity they need or could get outdoors. Also, this city has been more and more recommending that all cats stay indoors (when we adopted our newest, the adoption papers said - must stay inside) and the vet usually always has papers with info about why it's important to keep cats indoors here.
Back to the discussion at hand, I think my youngest cat is part-rabbit. When I have lettuce, watermelon, or cucumber, he jumps up and down, excited, and begs for it, but if someone in this house has meat and offers it, he runs off from it. The other two don't seem as interested in things like that, but I am seriously considering Evolution cat food, just to try out and see how they like it. I have a feeling the baby (he's 2, but still a baby to me/the youngest of the group) will jump for joy, the others I'm iffy about.