Info Sheets

Rabbits often feel warm to the touch, especially if you place your hand on an area where their fur is thin. This is because they have a normal body temperature which is higher than ours. A normal rabbit's body temperature is kept within a fairly narrow range of 103.3–104°F (38.5–40°C). However, this can vary slightly depending on environmental temperatures, stress, and even the time of year. If your rabbit has a fever (pyrexia) this means their body temperature has gone above the normal reference range. This can occur due to many different health conditions, so your veterinarian might need to investigate things further.

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Healthy rabbits will keep their body temperature constant, even when they are exposed to wide changes in environmental temperature. Changes in the body’s temperature are measured by special receptors (thermoreceptors). These detectors send signals to the body's organs that can lose or generate heat. If the body temperature goes up, more blood flows through the skin and heat is lost from blood flowing near the surface of the rabbit. In hot conditions the rabbit will also show behavioral changes such as seeking out a cool place to lie and will drink more water. When the environment is cold, shivering occurs (because muscle activity increases heat production), and rabbits may snuggle together for warmth and spend more time in their nest. This is called homeostasis, and the body is normally very good at maintaining a consistent temperature. However, issues can occur if the environmental temperatures become too extreme or if your rabbit has a condition that is making them unwell.

True fever is caused by the action of ‘pyrogens’ – substances that change the level at which the body temperature is maintained. Once the ‘normal’ body temperature has been reset, the rabbit now tries to keep body temperature at a higher level. Pyrogens include bacteria, viruses, toxins, some drugs, and natural substances released by the body in response to inflammation. In some cases, a moderate fever can be a good thing; bacteria may not grow so quickly at higher temperatures and so raising body temperature gives the rabbit a better chance of dealing with the infection. It is not always wise to suppress a fever without trying to find out what has caused it, and it is always better to try to treat the underlying cause if possible.

It can be difficult to know if your rabbit has a fever without getting them checked over by a veterinarian. You should not attempt to take your rabbit’s temperature yourself at home. This is because the inside of a rabbit’s rectum is very delicate compared to other animals, and it can be easily damaged with a rectal thermometer. Instead look out for signs that your rabbit is generally unwell such as reduced appetite, lethargy, changes in body posture, and reduced fecal production. Abnormal discharge, lumps, or sores could also indicate that your rabbit is sick. It is important to seek help as soon as possible from your vet, as rabbits can go downhill very quickly. Your veterinarian will perform a thorough examination which will include taking a rectal temperature, if required.

Since body temperature is so closely controlled in the normal rabbit, a fever is an indicator that something is wrong. In some diseases, short fever ‘spikes’ occur (where the temperature is suddenly raised for a short period only to drop to normal and then rise again later). In other diseases, persistent fever occurs, and the temperature is consistently above normal. A rabbit with a fever is usually depressed and may have a reduced appetite, but short-term moderate fever does not do any permanent damage to the body. If the fever gets very high (above 106.9°F/41.6°C) body tissues can be damaged, and it is important to try to bring the body temperature down as soon as possible. Fortunately, it is very rare for body temperature to rise this high, and this is often the result of heat stroke or serious seizures (fits) rather than infections. If you think your rabbit could be suffering from heatstroke it is important to dampen their fur with cool water and position them in front of an electric fan before calling a veterinarian for further advice. If your rabbit has a fever due to an underlying illness, the veterinarian can only give you an accurate prognosis once the exact cause has been determined. Some conditions may be easily treated whereas others carry a poor long-term outlook.

Most fevers in rabbits are caused by infections of some kind, but other disease processes like cancer and auto-immune conditions can also cause a raised temperature. Your rabbit’s body temperature may return to normal spontaneously or with the help of antibiotics and/or anti-inflammatory medications. But if their temperature remains high after a few days of treatment, or if they are showing other symptoms of disease, your veterinarian may want to undertake further tests to try to identify the cause of the problem. Investigation of an unexplained fever will usually require blood samples, X-rays, and ultrasound, but there may be other tests that need to be run, depending on your veterinarian’s initial findings. Rabbits are also highly susceptible to other issues like gut stasis when they have a reduced appetite. Supportive treatment may therefore also be required in some cases while your veterinarian works out the underlying cause of their problem. Hospitalization is needed for many unwell rabbits, to administer fluid therapy, provide assisted feeding, and closely monitor their condition. While some causes of fever are diagnosed easily, others can require several tests, some of which may need to be repeated. The exact treatment your pet requires will also depend on their diagnosis, though medication can help to make your rabbit more comfortable in the meantime. Your veterinarian will talk you through their plans and should also provide you with an estimate for the likely costs involved. Don’t be afraid to ask your veterinarian if you have any questions or if you need a further breakdown of the treatment costs. Your veterinarian wants the best outcome possible for your rabbit so they will be happy to discuss things in more detail with you. Never give medications to your rabbit without veterinary advice. Giving your rabbit non-veterinary prescribed medication is dangerous. Some human medications can be toxic to rabbits and can also make it harder for the veterinarian to work out what the underlying health problem is.