Skip to Main Content
Ask About Financing

Fever in Cats - A Pet Parent's Guide

Fever in Cats - A Pet Parent's Guide

If your cat has a fever it could be a sign of an underlying health issue that requires urgent treatment. Today, our Denver vets explain some of the causes of fever in cats, symptoms to watch for, and what to do if your kitty has a fever.

Fever in Cats

Just like humans, cats will often develop a fever if their immune system is fighting off an infection or disease. The normal body temperature for cats is around 100.4º to 102.5º Fahrenheit.  A fever is characterized by a temperature of more than 102.5º F in cats.

If your cat shows any of the signs of fever listed below it is essential to seek veterinary care. Cats that develop a fever higher than 106º F are at serious risk of damage to their vital organs. 

Signs of Fever in Cats

The signs of fever in cats vary depending on the underlying cause. If your feline friend has a fever you may notice one or more of the following symptoms: 

  • Lack of appetite
  • Weakness or lethargy
  • Shivering 
  • Rapid heart rate
  • Decreased activity 
  • Decreased drinking
  • Dehydration 
  • Poor grooming
  • Vomiting
  • Diarrhea 

How To Take Your Cat's Temperature

Taking your cat's temperature is fairly relatively forward. Simply use a digital thermometer aimed at your cat’s ear, or use a pediatric rectal thermometer for a more accurate reading. Never use an older style mercury thermometer when taking your pet's temperature! If the thermometer breaks it can be very harmful to your kitty's health.

The best way to accurately measure your pet's temperature and determine whether your cat has a fever is to use a pediatric rectal thermometer. Apply petroleum jelly to the thermometer to lubricate it, then gently insert it. It's important not to go too far as it could damage your cat's delicate rectal tissue. You may need someone to help you calmly restrain your cat while you insert the thermometer. Leave the thermometer in place for at least two minutes in order to get a correct reading.

If you think that your cat may have a fever but you are uncomfortable taking their temperature, contact your veterinarian right away to book an appointment. Your vet will be able to quickly assess your kitty's temperature and overall state of health.

Causes of Fever in Cats

Fevers generally occur in cats when their immune system is activated by conditions such as:

  • Bacterial and viral infections
  • Fungal infection
  • Internal injury
  • Trauma
  • Parasites
  • Autoimmune disease
  • Certain medications
  • A tumor
  • Immune-mediated inflammatory disease
  • Poisoning
  • Metabolic disorders
  • Endocrine disorders

Conditions that Can Cause Fever in Cats

Outdoor cats are at the highest risk for exposure to diseases than indoor cats. There are a number of serious conditions that can cause fever in cats, including:

Bobcat Fever in Cats (Cytauxzoonosis) 

Bobcat fever is an acute, sometimes fatal disease in cats caused by the bite of a tick infected with the Cytauxzoon felis parasite. This condition often strikes healthy, young adult cats that spend time outdoors.

Valley Fever (Coccidioidomycosis) 

Valley fever in cats is caused by the inhalation of the soil fungus Coccidioides immitis found in desert regions of the Southwestern United States. Symptoms of valley fever in cats include fever, lethargy, poor appetite, coughing, but can progress to severe joint and back pain, seizures and blindness.


Haemobartonellosis is an antibiotic-resistant bacterial blood infection seen in cats. This condition often leads to urinary tract infections and pneumonia that are very hard to treat.


Ehrlichiosis is a tick-borne condition that can lead to fever in cats. The signs of Ehrlichiosis in cats include fever, swollen lymph nodes, lethargy, decreased appetite, abnormal bruising or bleeding, and eye inflammation.

Milk Fever (Eclampsia) 

Eclampsia typically occurs in cats approximately 4 weeks after giving birth to kittens. Early signs of milk fever in cats include a stiff walk, restlessness and excessive panting.

Cat Scratch Fever (Bartonellosis) 

This condition can be transmitted between animals and from animals to humans. In cats, the disease is typically spread through contact with flea feces. Symptoms of cat scratch fever in cats include fever, swollen glands, lethargy, decreased appetite, and in some cases reproductive difficulties. 


This is one of the most common parasitic diseases. Toxoplasmosis in cats can lead to symptoms such as fever, diarrhea, cough, difficulty breathing, jaundice, seizures, and in severe cases this condition can be life-threatening.

What To Do If Your Cat Has a Fever

It is important to NEVER give your cat human medications without the explicit advice of a veterinarian! Many human medications, such as acetaminophen, can be extremely toxic to cats.

Make sure your cat stays hydrated by ensuring that they have easy access to fresh clean water and make sure they have a comfortable place to relax. 

If your cat has a fever that lasts longer than 24 hours or goes above 106º F contact your veterinarian to book an urgent appointment or visit your local emergency animal hospital right away.

Your vet will do a full examination of your cat to determine the cause of your pet's fever, and prescribe the best treatment to help restore your cat's good health. In some cases, even after an extensive veterinary examination, the cause may not be evident and your cat could be diagnosed with a fever of unknown origin (FUO). If your cat has moderate or severe dehydration, intravenous fluids may be used to help your cat feel better and fight off illness. 

Fever Coat in Cats

Fever coat (or stress coat) is a relatively uncommon phenomenon that occurs when a pregnant cat experiences an illness or severe stress which leads to a high fever.

During gestation the pigmentation of the developing kittens' coats is very sensitive to heat. If the pregnant mother has a high fever due to illness or prolonged stress, it has the potential to affect the coloration of her kittens' fur - this effect is often called 'fever coat'.

Fever coat most often appears as silver, grey, or cream-colored fur that become darker at the root. Fever coat can be beautiful and has no negative impacts on the kittens' overall health.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

If your cat is feeling under the weather our Denver vets are here to help. Contact Downtown Animal Care Center today to book an appointment for your feline friend.

New Patients Welcome

Downtown Animal Care Center is accepting new patients! Our experienced vets are passionate about the health of Denver companion animals. Get in touch today to book your pet's first appointment.

Contact Us

Book Online (303) 595-3561