Plant-based pet foods are growing in popularity for ethical and environmental reasons, but species-specific nutritional requirements mean welfare implications differ significantly between dogs and cats.
The welfare implications of plant-based pet food depend entirely on whether nutritional requirements of the individual species are met. For dogs, well-formulated vegan diets appear to support good health and the emerging evidence suggests they may be nutritionally adequate when properly designed. For cats, the risk is substantially higher because cats cannot synthesize several essential nutrients that must come from animal tissue in nature. Synthetic supplementation can theoretically compensate, but the long-term evidence base is limited. Pet owners who choose plant-based diets for their cats carry greater responsibility to verify nutritional adequacy through regular veterinary monitoring. The welfare of the pet must remain the primary consideration above the ethical motivations driving the dietary choice.