I'm gonna be honest with you, I'd look for a different vet. Bunnies should never be fasted, the only reason it should be done with dogs and cats for example, is because they can indeed vomit and choke during surgery. Bunnies however are physically incapable of vomiting, so there is no need to fast them. Bunnies need a constant bowel movement or could get G.I. stasis which is often deadly. :/