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Cat Scratch Disease

What is cat scratch disease (CSD)?

Cat Scratch Disease (CSD) is a bacterial infection caused by Bartonella henselae. It is transmitted to cats by flea droppings in a cat’s 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 may also spread Bartonella henselae to cats, but it is not clearly documented that ticks can spread CSD to people.

Does my cat carry this disease?

Not every cat or kitten will carry Bartonella henselae. The Centers for Disease Control and Prevention (CDC) estimates that about 40% of cats carry the bacteria at some time in their lives. Cats that carry this disease do not show any signs of illness, so 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 (cat bite, scratch, or where a cat licked an open wound). Rarely, people may also experience eye infections, severe muscle pain, or swelling of the brain.

How is it diagnosed?

Your doctor will diagnose CSD based upon your symptoms and exposure history. He/she will ask you about your history of cat bites and scratches, or whether you have had any interactions with a cat that may have been carrying the bacteria.

What is the treatment?

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

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

If you have been bitten or scratched by a cat, you should be sure to wash the area thoroughly with running water and soap. If you develop an infection where you were scratched or bitten by a cat, or develop symptoms such as a fever, headache, swollen lymph nodes, or fatigue, you should contact your doctor.

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 that you may have.
  • Keep your cats indoors and away from stray cats.
  • Since immunocompromised individuals are at a greater risk of contracting CSD, these people should avoid owning a cat that is less than one year old.
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