We had a rabbit with our two cats for a short period of time and they got along famously. At first the cats were leery and it was funny to watch. Once everyone got acquainted it was game on. Rabbits and cats are good combos. Probably better than introducing a 3rd full grown cat into the mix. Sadly we lost the rabbit not too long after, but he had a good time while he was with us. It ended on a high note.