Being a prey species, rabbits will mask signs of illness or disease for as long as possible. This makes it really important to know the subtle signs of illness to look out for. So, let’s explore how you can tell if a rabbit has a fever, and what causes fever in rabbits. 

How can you tell if a rabbit has a fever?

The only way to know for sure if a rabbit has a fever is by checking their rectal temperature. This involves a thermometer being gently inserted into their bottom. A fever is generally classed as over 40C in a rabbit. It’s safest for your vet to check this, rather than trying at home. Rabbits get stressed very easily, especially when they are poorly. They also have very delicate bottoms, so you could accidentally cause damage with the thermometer.

There are some signs to look out for at home, which could indicate that your rabbit has a fever. These include:

  • Reduced appetite
  • Lethargy (sleepiness)
  • Changes in behaviour
  • Changes in their stool (such as smaller, fewer or unusually shaped pellets)
  • Teeth grinding 
  • Changes in their breathing (such as breathing faster or more noisily than usual)

These are also signs of pain or illness in rabbits, not necessarily with a fever. Either way, if you notice any of these signs in your bunny, even if they are mild, you need to take them to a vet as soon as possible.

What causes a rabbit to have a fever?

Much like in humans, many infections can cause a fever in rabbits. Some of the more common causes of fever in rabbits include:


Myxomatosis is caused by a virus, and is transmitted via blood sucking insects (such as fleas or mosquitos), through contact with other rabbits, or through contact with objects in the environment (such as bedding). Symptoms usually start with puffy eyes, ears, face, genitals and/or bottom. As the disease progresses, rabbits will develop a fever, become lethargic and stop eating.

Viral Haemorrhagic disease (VHD)

VHD is another serious viral disease, which is spread in the same way and causes internal bleeding and liver failure. Symptoms include unexplained bleeding from orifices (eyes, ears, nose or bottom), fever, lethargy, reduced appetite, breathing difficulties and collapse. Sadly, it can also cause sudden death.


Pasteurella multocida is a bacteria that causes the ‘snuffles’; an upper respiratory infection with symptoms such as sneezing and discharge from the eyes and/or nose. It can also cause other respiratory infections, as well as abscesses in various locations, such as the tooth roots, the jawbone, skin and internal organs. Luckily, many cases are mild. However, if left untreated the infection can become serious.


Rabbits are prone to developing large, pus filled chambers, or abscesses, following injury, and these can lead to a very high fever.

There are many other possible causes of fever in rabbits, such as pneumonia or uterus infections, or indeed any bacterial infection, so this list is not exhaustive! 

What do I do if my rabbit has a fever?

If you suspect that your rabbit has a fever, or they are showing any signs of illness, you should take them to a vet as soon as possible. Let the veterinary team know any symptoms you are concerned about, as they may well decide that your rabbit needs an urgent appointment. Remember, rabbits are prey animals, so they mask signs of illness very well. This means that by the time they show symptoms, they are often very ill indeed. 

You should never give any human medicine, or medicine intended for other animals, to your rabbit. Rabbits are very sensitive so this can be very dangerous, and potentially fatal.

Final thoughts 

The good news is that some of these diseases can be prevented! We can vaccinate rabbits against both myxomatosis and VHD (viral haemorrhagic disease) every 6-12 months. So, if your rabbit isn’t up to date with their vaccinations, please book an appointment with your vet, it’s not too late! 

Remember, rabbits hide illness and injury. So spend some time watching your rabbit, and learn what is ‘normal’ for them. Any deviation from their normal behaviour or routine warrants a trip to your vets, and sooner rather than later.

You might also be interested in: