I have 4 cats & 3 rabbits. Initially, we did not let the rabbits out unsupervised w/ the cats. I had an issue w/ marking on cat beds & rabbits using the cat litter boxes. I got tired of all the drama so didn’t bother w/ the minglng of species. Over time everyone seemed to get better. I eventually let them all roam free now. They have all learned to get along and I have no problems.
Our new bunny, Chewbacca, is NOT allowed to free roam. She chews EVERYTHING! Loves to potty on Max’s cat bed. She also likes to play in the kitty litter box. When we let he out, we have a gate in front of the closet where the boxes are located. Fortunately, the kitties have learned to be patient at the gate until we let them into their litterboxes. She loves to lay w/ the cats, next to their beds. She just really needs to be supervised, not b/c the cats will do anything to her…they are getting too old to care, but b/c she is so naughty!