Cat Scratch Disease Fact Sheet

Revised 10/2013

Download a print version of this document:
Cat Scratch Disease Fact Sheet (PDF)

What is Cat Scratch Disease?

Cat Scratch Disease (CSD) is an uncommon infection caused by the bacteria Bartonella henselae. Generally people who get CSD are either bitten or scratched by a cat before they get sick. Most healthy people do not develop any symptoms, but those with a mild infection usually get better without any treatment.

What are the symptoms of CSD?

Symptoms include:

• swollen lymph nodes near the site of the bite or scratch
• fever
• headache
• fatigue
• poor appetite
• skin pustule at site of the bite or scratch; usually develops 1 to 2 weeks before lymph nodes begin to swell

Symptoms usually begin 3 to 14 days after being bitten or scratched by an infected cat.

People with a weakened immune system due to disease or medication are more likely to have complications from CSD. These complications are rare and include Parinaud’s oculoglandular syndrome, an eye infection that causes inflammation of the optic nerve and can lead to blindness, and bacillary angiomatosis, a systemic illness characterized by lesions on the skin, mucosal surfaces, liver, spleen and other organs.

How is CSD treated?

Antibiotics may be used to speed recovery in cases of acute or severe illness but most people do not require treatment. Recovery occurs spontaneously within 2 to 4 months.

How is CSD diagnosed?

A diagnosis is made based on appropriate exposure history, symptoms, and a blood test that can detect antibodies to B. henselae.

Can I get CSD from my cat?

Yes, it is possible to get CSD from your cat. Most people get CSD from cat bites or scratches. Kittens are more likely to be infected and therefore able to pass the bacteria to humans than adult cats. Cats are the natural reservoir for the bacteria that causes CSD, and generally do not show any signs of illness. Therefore it is impossible to know which cats can spread CSD to you.

Fleas are responsible for transmitting B. henselae between cats and it is believed that transmission to humans occurs through contamination of bites or scratches with flea excrement. There is no human-to-human transmission of CSD.

How can I reduce my chances of getting CSD from my cat?

• Maintain excellent flea and tick control
• Avoid rough play with cats
• If you have an open wound do not allow a cat to lick it
• Thoroughly wash the site of a bite or scratch with soap and water
• Adopt or buy cats that are in good health and without fleas