I guess is a personal choice... I mean, if humans can live in a vegan diet why couldn't the pups?
But I know that when I put the bowls down with meat and all sorts of veggies, these end up on the floor and meat is the first thing gone. I am no expert by any means, but my whole life I heard that dogs were carnivores and they needed the meat in their diets.
Even I am not a big meat eater, but I do appreciate the nice steak once in a while