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Cat Scratch Disease

This fact sheet answers frequently asked questions about cat scratch disease (CSD). 

Cat scratch disease (CSD) is a bacterial infection caused by Bartonella henselae. Cats get it from flea droppings in their fur or claws. The bacteria spreads to people when an infected cat bites, or scratches, or licks someone’s open wound. Young children and people with weak immune systems are the most likely to get CSD. Ticks can also spread Bartonella henselae to cats, but it is not documented that ticks can spread CSD to people.

The basics

Does my cat carry this disease?

Not every cat or kitten will carry Bartonella henselae. The Centers for Disease Control and Prevention (CDC) estimates about 40% of cats carry the bacteria at some point in their lives. Cats that carry this disease do not show any signs of illness. You cannot tell which cats can spread the disease to you. Kittens and feral cats are the most likely to spread the disease because they are more likely to bite or scratch.


What are the symptoms of CSD?

The symptoms of CSD generally include fever, enlarged lymph nodes, and swelling near the site of infection. In rare cases, people may also experience eye infections, severe muscle pain, or swelling of the brain.

How is it diagnosed?

Your health care provider will diagnose CSD based on your symptoms and exposure history. They will ask about your history of cat bites and scratches, and whether you have had any interactions with a cat that may have been carrying the bacteria.


What can I do to prevent CSD?

Follow these tips to reduce your risk:

  • Proper flea treatment is the most effective prevention against CSD. Ask your veterinarian about the best flea treatment for your cat
  • Avoid “rough play” with cats, especially kittens. This includes any activity that may lead to cat scratches and bites
  • Wash cat bites and scratches immediately and thoroughly with running water and soap
  • Do not allow cats to lick open wounds
  • Keep your cats indoors and away from stray cats
  • Immunocompromised individuals are at a greater risk of contracting CSD. These people should avoid owning a cat that is less than one year old


What is the treatment?

Most cases of CSD will resolve on their own without treatment. If necessary, your health care provider may prescribe an antibiotic.

What should I do if I think I may have CSD?

After a bite or scratch from a cat, wash the area thoroughly with soap and running water. If you develop an infection at the site of the scratch or bite, or if you develop symptoms you should contact your health care provider.

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