Everything JamieK typed is accurate. Being around dogs all day, working in a pet store, etc. doesn’t make one an expert on nutrition. No offense intended at all. Dogs evolved to be scavengers, getting nutrition from plant and animal sources. That makes them omnivorous.
Since plant-based foods contain more vitamins and minerals per calorie compared to animal-based foods, there are legitimate reasons to consider vegan or mostly-vegan diets superior.
The question of digestive enzymes or gut flora could tip the balance back toward meat, but that is largely unexplored territory. Humans have comparatively large digestive systems, but that is more because our ancestral diets contained large amounts of raw plant matter (more energy required to digest). Assuming that vegan dog food isn’t raw, and is prepared to optimize digestion and nutrient uptake, it could certainly work.
Again these are just the facts. If you disagree then your notion of common sense is flawed.
