Precisely, even such a minor deviation from the natural diet of cats can cause serious health issues.

General scientific consensus is that commercially available vegan cat food is nutritionally inadequate (despite claiming otherwise).

General consensus amongst veterinarians is that feeding cats vegan or vegetarian diets is likely to cause health issues.

(one amongst several articles)

https://www.petmd.com/cat/nutrition/can-cats-be-vegan-or-vegetarian

Also, militant is a frequently used and suitable word in this case - acting grammar nazi isn’t really helping your case here. (unless you aren’t intensely devoted to not serving meat? If so, my apologies lol)