May 7, 2025, 5:27 pm | Read time: 4 minutes
The causes of fever in cats can be varied. While elevated temperature can be triggered by stress, fever is often a sign of a serious illness or infection.
Fever is a common but often overlooked sign that something may be wrong with the health of our cats. As a responsible cat owner, it’s important to recognize the symptoms early and respond appropriately. PETBOOK explains how to measure a cat’s fever, what causes it, and what to do about it.
Overview
When Do Cats Have a Fever?
Fever is an increase in body temperature above the normal range, triggered by an immune response to pathogens or inflammation. A cat’s normal body temperature ranges from 100.4 to 102.6 degrees Fahrenheit. Temperatures above 103.1 degrees Fahrenheit are generally considered a fever.
Symptoms: How to Recognize Fever in Cats?
Fever is not always easy to detect, as cats can hide their symptoms well. The following signs may indicate a fever in a cat:
- Lethargy or apathy
- Loss of appetite
- Increased body temperature (feels warm, especially on ears or paws)
- Rapid breathing or panting
- Hiding or withdrawal
- Shivering or muscle tremors
- Unkempt coat
If you notice these symptoms in your cat, you should measure its internal body temperature.
How Do I Measure a Cat’s Fever?
The most reliable measurement is with a rectal thermometer. It should be thoroughly cleaned and disinfected beforehand. To make the process as comfortable as possible for the cat, it’s recommended to use some medical lubricant for insertion. Not every cat will easily allow the measurement. To protect yourself and avoid injuries, it’s important to restrain the cat. Ideally, two people are involved. One person can calmly hold the cat while the other inserts the thermometer.
Alternatively, you can use an infrared device. This measures the temperature at the cat’s ear. While easy to use, this method is significantly less accurate than a conventional thermometer.
Possible Causes
Fever is a defense reaction of the body and should be seen as a sign that the cat is fighting something. Infectious causes are often responsible. These include bacteria such as streptococci, anaplasmas, and chlamydia. Viral diseases can also cause fever in cats, such as Feline Immunodeficiency Virus (FIV), Feline Infectious Peritonitis (FIP), or Feline Leukemia Virus (FeLV). Other infectious causes can be fungal diseases or parasites like lungworms or toxoplasmosis.
In addition to infectious diseases, non-infectious causes can also trigger fever in cats. Internal or external tissue inflammations are particularly common culprits. Dental diseases (such as FORL) or autoimmune diseases can also be causes of fever.
When Should I See a Vet?
If the temperature rises above 103.1 degrees Fahrenheit and lasts for more than 24 hours, a visit to the vet is essential. Temperatures above 105.8 degrees Fahrenheit are considered an emergency. Depending on the cause, the vet may prescribe antipyretics, anti-inflammatories, or infusions.
Feline zoonoses: Cats can transmit these diseases to humans
Editor: ‘My best tips for walking in high temperatures’
Heatstroke in dogs in the car – the underestimated danger
What to Do if the Cat Has a Fever?
Until veterinary treatment is available, there are several things you can do at home to support your cat in this condition. Ensure a calm and stress-free environment where your cat can recover. Fresh water should always be available, as adequate hydration is particularly important now. Cooling measures can also be applied if necessary. You can place a damp cloth on the cat’s paws or belly. Make sure the cloth is not dripping wet. If the cat shows signs of discomfort, you should refrain from this measure. You don’t want to add stress to your pet in an already weakened state.
Even if it’s difficult for a pet owner to see their animal sick or even suffering, you should never administer medication yourself. Antipyretics like acetaminophen or ibuprofen are highly toxic to cats.
Conclusion: A temporarily elevated temperature in a cat is not always a sign of a serious illness. Stress or high temperatures in summer can be behind it. However, if the temperature continues to rise and persists, it should be taken as an important warning signal and not ignored.
My Tips for Measuring a Cat’s Fever
“Whether a cat has a fever can be an important indicator of whether you should go to the vet right away. Therefore, it’s worth practicing taking a cat’s temperature. However, you can first check if the cat’s ears feel hot. If the armpits are also hotter than usual, you should measure more precisely. I use a regular thermometer, which I coat with a bit of petroleum jelly. Some cats tolerate the procedure better if distracted with a particularly tasty treat. Tuna is very popular with most animals. Especially younger cats are often so busy licking it up that you can easily insert the thermometer. If you don’t have a separate thermometer for the cat at home, you can also use your own and cover it with a disposable latex glove.”