Cat-Scratch Fever

Medically Reviewed by Stephanie S. Gardner, MD on April 26, 2022
4 min read

Cat-scratch fever is an infection caused by a kind of bacteria called Bartonella henselae (it's also sometimes called Bartonella henselae infection). You can get it if a cat that has this type of bacteria licks an open wound on your skin or bites or scratches you.

Cat-scratch fever, also called Cat-scratch disease (CSD), happens most often in children and teens.


About 40% of cats and kittens carry Bartonella henselae in their mouths or under their claws. They get this by scratching or biting at infected fleas. They can also pick it up by fighting with other cats that have it.

Most cats that are infected don’t show any symptoms. But in serious cases, they could have trouble breathing or come down with infections in their mouth, eyes, or urinary tract.

If a cat that has Bartonella henselae bites or scratches you hard enough to break the skin, then the bacteria can get into your body. You can also get infected if a cat licks a sore, wound, or scab that you have.

Not everyone who’s been licked or scratched by a cat needs to go to the doctor. If you’ve been infected with CSD, you’ll have symptoms.

These don’t happen right away. Most of the time, they appear days after you’ve been around a cat.

The first sign is often a red bump, sore, or blister at the site of the scratch or bite. This may not hurt, but it often has a crust and could contain pus.

Within the next 2 weeks -- and even after the bump has healed -- you could have:

The lymph nodes that swell are often near the infected area. For instance, if a cat bit your arm, the glands in your armpit could swell or fill with pus.

In very rare cases, CSD causes serious problems that affect your bones, joints, eyes, brain, heart, or other organs. These are most likely to happen in children younger than 5 years old or people who have a weakened immune system.


If you tell your doctor that you were scratched or bitten by a cat, they may be able to diagnose you by looking at your symptoms. If not, you might need to get a blood test done. Your doctor may look for CSD by taking a tissue sample from your lymph node.

For people in good health, CSD will likely go away without treatment. Until it does, you can take an over-the-counter anti-inflammatory medicine like ibuprofen (Advil, Motrin, Nuprin) or naproxen (Aleve, Anaprox, Naprosyn) sodium to ease swelling and pain. A hot compress can help, too.

To relieve very tight, painful glands, your doctor may gently insert a needle into them and drain the fluid.

If you have problems with your immune system or your symptoms haven’t gone away in 2 months, your doctor will likely prescribe antibiotics. This can prevent the infection from spreading to other places in your body, like your liver or bones. You may need to take this medicine for several months.

You can keep your family pet. A few simple steps can help you avoid getting CSD.

  • Be cautious if you touch or pet stray cats. Since they spend time outdoors, there’s a higher chance that they’ve come into contact with fleas and have CSD.

  • Avoid “rough play” with your cat. This raises your chances of getting scratched or bitten.

  • Take care of your pet. Trim your cat’s nails and use a product to prevent fleas. Check with your veterinarian about the best type to use, since not all over-the-counter products are safe.

  • Wash your hands often. Clean your hands with soap and water after petting or playing with your cat. If you’re scratched or bitten, you’ll also want to wash the area right away with soap and water. The same goes if your cat happens to lick an open sore, scab, or wound.

  • Adopt an older cat if you have health issues. If you have a weakened immune system and want to adopt a cat, choose one that’s at least a year old. Young kittens are more likely to have CSD.