Rabbits naturally hide illnesses from predators and so do our domestic rabbits. You need to pay close attention to your rabbit’s behavior and eating habits. If your rabbit is not eating/drinking/pooping/peeing, these are serious symptoms. Take your rabbit to a rabbit-savvy vet immediately. A change in either of these is a a sign to take your rabbit to the vet. Do not wait for the “illness” to pass, many issues are deadly and will cause death within 24 hours of onset.