Cat scratch fever is an infection caused by a bacteria. It can start after a scratch or bite of a cat, kitten, or rarely a dog.

Cat scratch fever usually goes away without treatment. For some it can become a serious condition. It will then need medical attention.


The bacteria that causes cat scratch fever are found in fleas. They are passed on to cats through flea bites.

Risk Factors

The most common risk factor is being bitten or scratched by a cat or kitten.


Cat scratch fever may cause:

  • A crusting sore or blister that forms over the site of a cat scratch or bite
  • Swollen, painful lymph nodes
  • Low fever
  • Flu-like symptoms such as weakness, nausea, chills, loss of appetite, and body aches
  • Eye involvement

Swollen Lymph Nodes

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Rarely, people may develop serious complications such as infections of:


Your doctor will ask about your symptoms and health history. A physical exam will be done. You may be asked about contact with animals. Your doctor may then be able to diagnose cat scratch fever. Blood tests may be needed if the diagnosis is not clear. They will help to find the cause of the infection.


Cat-scratch fever will often pass on its own, without treatment. Talk with your doctor about the best plan for you. Treatment options may include:

  • Over-the-counter pain relievers—to manage discomfort
  • Antibiotics—may be used for people who are very ill or have weak immune systems
  • Lymph node drainage—very swollen or very painful nodes may need to be drained; it can be done through a needle


To help reduce your chances of cat scratch fever:

  • Keep your pets free of fleas.
  • Try to avoid scratches or bites from a cat or kitten.

Centers for Disease Control and Prevention

Winn Feline Foundation


Canadian Veterinary Medical Association

Health Canada


Cat-scratch disease. Centers for Disease Control and Prevention website. Available at: Updated April 30, 2014. Accessed December 6, 2017.

Cat-scratch disease. EBSCO DynaMed Plus website. Available at: Updated August 24, 2017. Accessed December 6, 2017.

Klotz SA, Ianas V, Elliott SP. Cat-scratch disease. Am Fam Physician. 2011;83(2):152-155.

Last reviewed November 2018 by EBSCO Medical Review Board David L. Horn, MD, FACP  Last Updated: 7/3/2018