Rabbits are very good at hiding the fact they're ill because in the wild any signs of illness make them an easy target to predators. Any changes in your rabbit are to be treated as serious, as once a rabbit shows signs of being ill, such as going off his food, he is already in desperate need of a vet. You can never be too cautious with rabbits - if you're even slightly worried about your rabbit, visit your vet STRAIGHT AWAY.
This is a major signal that your rabbit is in URGENT need of a rabbit-savvy vet. DON'T DELAY in taking him there. You cannot leave it and hope he will recover on his own, once a rabbit is behaving like this it is highly unlikely they will recover without medical care.
Rabbits are grazers and need to constantly eat (especially hay and grass) to keep their gut moving. If your rabbit has gone off his/her food this is serious and could quickly send them downhill. Rabbits should never be starved (even before operations). If your rabbit has stopped eating GET HIM TO THE VET STRAIGHT AWAY. Failure to do this could be fatal.
These are major signs that your rabbit is in pain, and may be accompanied by cold ears, or ears laying flat against their back. It is another emergency sign that you MUST take your rabbit to the vet STRAIGHT AWAY.
No droppings or very small poos are a sign your rabbit's digestive system isn't working properly. No poos at all is serious, and even if your rabbit is still eating, if she's not producing poos you MUST take her to a vet IMMEDIATELY. It signals Stasis which is a common and deadly condition. The earlier you take your bun to the vet the higher the chance your rabbit has of surviving.
If your rabbit gets poo stuck around his rear-end a lot then firstly look at his diet - is it too rich? See our page The importance of poo. Various illnesses could also be a cause so ask your vet for advice.
This is flystrike and can kill your rabbit within a day. Take him/her to a vet as soon as possible. Read more about Flystrike on our page: What is flystrike?
If your rabbit has not always had an aggressive temperament, it is most likely he or she has reached sexual maturity (around 4 months) and the hormones have kicked in. You need to get your rabbits neutered to keep them calm and happy, as well as avoiding breeding and preventing cancers (80% of female rabbits get uterine cancer which neutering can prevent). You can read more about neutering on our page: Why neuter your rabbit?
These are only a few signs of illness. Get to know your rabbits and look for subtle changes. Take them for regular vet checkups eg. at the same time they have their injections. With rabbits you should NEVER delay in getting them to a vet. Register your buns with a rabbit-savvy vet so you know where to take them in case of an emergency.