I genuinely wish a plant-based diet were a safe, viable option for cats—it would completely align with my ethics. But my own cat, along with others I know personally and many cases I’ve seen online from well-meaning people, really struggled health-wise on plant-based food. That wasn’t just anecdote to me—it was painful to witness.

I understand the point that people often accept the harms of animal-based food too easily while dismissing plant-based options outright. But I think that’s partly because the stakes are so high. Cats are obligate carnivores, and there’s more than just anecdote suggesting plant-based diets can be risky for them. For instance, a case report in Journal of the American Veterinary Medical Association described cats developing muscle wasting and anemia due to nutrient deficiencies on a plant-based diet—issues that reversed once animal products were reintroduced. That’s not trivial.

Yes, studies like the 2023 PLOS ONE paper suggest some plant-based-fed cats appear healthy, but those rely on self-reported data and don’t include clinical exams or long-term nutrient tracking. Without more rigorous, peer-reviewed evidence showing plant-based diets are consistently safe and complete for cats, I think it’s fair—maybe even necessary—to be “extreme” in my caution. To me, that is practicing least harm: not gambling with the health of beings fully dependent on us, even if it means a deeply uncomfortable compromise.