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What is cat scratch disease? It’s a common benign infectious disease found after a scratch or bite from a cat.

People can get CSD from the scratches of domestic or feral cats, particularly kittens. The disease occurs most frequently in children under 15. Cats can harbor infected fleas that carry Bartonella bacteria. These bacteria can be transmitted from a cat to a person during a scratch. Some evidence suggests that CSD may be transmitted directly to humans by the bite of infected cat fleas, although this has not been proven.

CSD occurs worldwide and may be present wherever cats are found. Stray cats may be more likely than pets to carry Bartonella. In the United States, most cases of CSD occur in the fall and winter.

Ticks may carry some species of Bartonella bacteria, but there is currently no convincing evidence that ticks can transmit Bartonella infection to humans.


Enlarged lymph node resulting from cat scratch disease. Used with permission of NEJM.

  • Fever
  • Enlarged, tender lymph nodes that develop 1–3 weeks after exposure
  • A papule or pustule at the inoculation site

Rarely, unusual manifestations such as eye infections, severe muscle pain, or encephalitis may occur.


Good veterinary care is important to your health and the health of your pet.

  • Avoid rough play with cats, particularly strays and kittens, to prevent scratches. This is especially important for immunocompromised individuals. Wash hands promptly after handling cats.
  • Treat cats for fleas using fipronil and other spot-on treatments. Check with your veterinarian. Permethrin should not be used on cats.
  • Use a flea collar or similar topical preventive on dogs (fipronil, methoprene, imidocloprid, or permethrin), especially if you have both cats and dogs in your household.
  • Keep cats indoors and away from stray cats.
  • Immunocompromised individuals should avoid owning cats less than one year of age.