Require a maker credit for fursuit photos
So, you know how it's a rule that you need to credit the artist for art posts? Do that, but do it for Fursuit posts. Fursuits are made by people, oftentimes commissioned by the wearer, and can be seen as a piece of art.
Fursuit images can also be stolen, and used to fabricate your identity (in the same way that stealing art of a certain character would).
require fursuit images to require the credit for the fursuit's maker