A normal temperature in cats ranges from 100.4° to 102.5° Fahrenheit. A fever in cats occurs when temperatures exceed 102.5ºF. Although fevers can be helpful in fighting disease, a fever over 106ºF can cause organ damage. Contact the veterinarian immediately if your cat has a high fever.
Learn about the causes, signs and symptoms of fever in cats and what you need to know about taking your cat's temperature and caring for a cat with a fever.
Causes of a fever in cats
An increase in body temperature above normal is called hyperthermia. Abnormal or unregulated hyperthermia in cats can result from a very hot environment or increased muscle activity, for example. However, a fever is a specific and regulated type of hyperthermia. It develops when the set point is increased in the hypothalamus, a part of the brain that acts as the body's thermostat. A fever usually occurs when the immune system is activated by conditions such as:
A bacterial, viral, or fungal infection
Injury due to trauma
Taking certain medications
Diseases such as lupus
A fever lasting more than two weeks for no apparent reason is called fever of unknown origin (FUO).
Signs of Fever in Cats
Illnesses that cause fever in cats can also cause certain telltale behaviors. These behaviors, which have evolved in wild animals to help them survive disease, allow cats to conserve the energy needed to produce a fever. Fevers fight disease by stimulating the immune system and slowing the growth of bacteria and viruses.
Watch for these signs of fever:
loss of appetite
Lack of energy or activity
Reduction in drinking
Chills or rapid breathing
Your cat may also show other specific signs of illness, such as sneezing, vomiting, or diarrhea.
Tips for taking a cat's temperature
The only way to know for sure that your cat has a fever is to take its temperature.
A pediatric rectal thermometer is the most accurate method of taking a cat's temperature. A digital thermometer is safer than a glass thermometer. It won't break if you drop it, and it gives a signal when it's time to check the reading. You can buy one from your veterinarian or at the pharmacy.
1. Before you begin, get out all the supplies you will need:
A lubricant for the thermometer, such as petroleum jelly
Alcohol and paper towel to clean the thermometer
A cat treat
2. Shake a glass thermometer so that the mercury is below the 96º line. To check, hold it up to the light and rotate it. To use a digital thermometer, turn it on.
3. Coat the tip of the thermometer with a lubricant.
4. Have an assistant restrain your cat with the rear end facing you. Or if you are alone, cradle your cat's body firmly against you with one arm.
5. Gently lift the tail and slowly insert the thermometer into the anus. Gently roll the thermometer from side to side to relax the muscles. Once this happens, insert the thermometer about an inch into the rectum, but don't force it.
6. Take out a digital thermometer when you hear the beep. Leave a glass thermometer in place for about two minutes.
7. Remove and clean the thermometer with alcohol. Read the temperature, by holding a glass thermometer to the light and turning it.
8. Give your cat a treat if it hasn't vomited.
Cat Fever Care
Cats showing signs of fever for more than 24 hours or a fever above 106º F at any time should consult their veterinarian. The veterinarian can perform tests to determine the source of the fever and take steps to treat the underlying problem. If a bacterial infection is the source, for example, antibiotics may be needed. Moderate or severe dehydration is treated by administering intravenous or subcutaneous fluids.
Never give your cat medication without the advice of your veterinarian. Certain fever medications, such as acetaminophen, are toxic to cats.