So many omnis here wtf. Here's a study on:

heart disease
dental disease
skin disease
hormone problems
stomach and liver problems
urinary problems
eyesight problems
kidney problems

in vegan and non-vegan cats. Plant-based cats are healthier on all fronts.

I know of a couple very healthy plant based cats who are fed Evolution, here's an intro pack . I've also heard good things from Benevo and Vecado. There's a vegan animal care discord server here.

EDIT: more sources

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5035952/

https://www.vegansociety.com/whats-new/blog/vegan-animal-diets-facts-and-myths

https://www.amipetfood.com/en/products/products-for-cats/amicat

https://vecado.ca/pages/compare-brands?utm_source=Vecado+Newsletter&utm_campaign=1173910fe2-w29-Dry-food-analytics&utm_medium=email&utm_term=0_3500338e58-1173910fe2-235041505&mc_cid=1173910fe2&mc_eid=c567961247

https://vecado.ca/blogs/news/vegan-cats-live-long-and-healthy-lives-according-to-new-study