Fever in cats can happen for a variety of reasons. In this article, we will discuss the most common symptoms, as well as some common causes of fever in cats. We will also discuss what you as pet owners can do to help your cats if you suspect they may have a fever. If you have any suspicion that your pet may have a fever and/or be unwell, it is important to always contact your vet for individual advice for your pet.

Table of contents

First off, what is a fever?

A fever is a rise (elevation) in core body temperature.

It is important to remember that our feline friends have a different normal range for their body temperature to us humans. A cat’s normal body temperature range is between 38.1 – 39.2 degrees Celsius. This is the equivalent of 100.5 – 102.6 degrees Fahrenheit. 

In humans, by comparison, a body temperature over 38 degrees Celsius (100.4 Fahrenheit) is considered a fever. So cats have much higher normal body temperatures than humans. 

What causes a fever?

A variety of causes can cause a fever. Most commonly, our cats will have a fever because their body is trying to fight off an infection. This may be a bacterial, viral, parasitic, or even fungal infection. 

When our cats have an infection, part of their immune systems’ response to fight this infection is to raise the core body temperature. There is a specific part of the brain called the hypothalamus, which is responsible for this rise in body temperature. The aim of this raised temperature is to try and kill the infection (such as bacteria) that is in the body, and to help our cats recover from the infection. The immune system is effectively trying to “cook and kill” the infection!

Some of the most common infections that cause fever in cats include: 

  • Skin infections (including cat-bite abscesses)
  • Ear infections
  • Chest infections 
  • Urinary tract infections (UTI)
  • Viral infections of different parts of the body, including the chest 

Cat-bite abscesses are quite a common cause of fever in our cats. These occur when they get into a fight with another cat, who bites their skin. This bite transfers bacteria from the biting cat’s mouth into the victim cat’s skin, which can lead to a pus-filled abscess infection and a fever as the body attempts to fight the infection.

Cancer, unfortunately, can also be a cause of fever in cats, although infection is more common. There are different tests that can be carried out if your vet suspects this could be a cause of your cat’s fever.

Very rarely, cats can get fever due to their immune systems not working properly which can cause fever as a result.

What are the symptoms of fever?

Even though fever is an extremely important tool for the immune system, it can make our cats feel poorly. 

Cats with a fever can often show the following symptoms:

  • Lethargy (tiredness/lack of energy)
  • Sleeping more than usual
  • Ears/ nose/ legs hot to touch
  • Increased or decreased thirst
  • Decreased appetite/hunger
  • Dull or sunken eyes
  • Vomiting 
  • Diarrhoea
  • Shivering/shaking

If your cat is showing any of these symptoms, it is very important to get in contact with your veterinary practice immediately. Your vet will be able to advise on the next best step for your cat, which may involve an examination at the practice/clinic. 

It is important to remember that a fever generally occurs as a result of an infection (or another issue) affecting the body, so your cat may need veterinary care both for their fever and also for whatever is causing their body’s fever in the first place (such as a possible infection).

How can I take my cat’s temperature?

Human temperatures are usually taken with a thermometer in the mouth. However, cats generally will not tolerate this, and there is a risk of getting bitten if you startle your cat trying to put something in their mouth, especially if they are feeling poorly.

Instead, if you wish to try and take your cat’s temperature, you can very gently try to take a rectal temperature. Apply a little petroleum jelly or KY jelly to the tip of a paediatric (infant) thermometer to lubricate it. Then gently and slowly insert it 1-2cm into the anus (your cat’s back passage). Be extremely careful not to use any force or pressure, as this could risk damaging your cat’s internal tissues. Take the reading when the timer on the thermometer beeps. If your cat becomes upset or struggles, stop immediately. If the thermometer reads a body temperature above 39.2 degrees Celsius then there is a good chance your cat has a fever.

It is very important to remember that things like poo or gas in the rectum can affect thermometer accuracy. Therefore, it is vital to contact your vet if you have any concerns that your cat may have a high temperature (fever) even if you cannot get a thermometer reading at home. 

If in any doubt, or if your cat objects, seek veterinary advice.

What can I do to help my cat with a fever?

If you think your cat might have a fever, or if they have any of the symptoms above, it is recommended to contact your veterinary clinic to get your cat checked over by a vet. It is important that your cat has constant access to clean, fresh water to drink. Avoid wrapping them up in blankets as this can make your cat very uncomfortable. 

It is extremely important to note that many human medications are highly toxic to cats. Paracetamol (Calpol/Panadol) is highly poisonous to cats. Even a very small amount of paracetamol can be enough to kill a cat. For this reason, never give cats human medications. 

Instead, contact your veterinary practice as soon as possible to get your cat booked for a check-up sooner rather than later.

What will happen when I bring my cat to the vet for a fever?

Your vet will first carry out a physical exam of your cat. This usually includes listening to their heart and lungs to check for any increased heart or breathing rate. They will take and record your cat’s temperature, their weight and check their gum colour. They will also check other body systems throughout their physical exam. 

The findings from this physical exam, along with the history you give of your cat’s symptoms will help your vet come up with a plan to help your cat. Your vet may recommend carrying out additional tests to help get a diagnosis of what may be causing your cat’s fever. These may include some blood tests and possibly an ultrasound exam of your cat’s chest and belly. These tests can also be very important to help rule out certain causes of fever, such as some viral infections.

Sometimes, a course of antibiotics can be sufficient to help your cat recover from fever if it is caused by an infection such as a cat-bite abscess. In other cases, your cat may need to be hospitalised for medications and special medical treatments.

Your vet will work with you to make the best plan for your cat. They will also recommend certain treatments to help them feel better. This might include intravenous fluids (a drip) to help rehydrate your cat, and medications to help them feel less poorly. 

Conclusion

Your cat having a fever can be a scary experience, especially if they are showing symptoms of feeling poorly too. Seeking prompt veterinary advice will help to give your pet the best chance of making a recovery from their fever. 

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