What is cat scratch fever and what causes it?

Cat scratch fever is a mild to severe disease that can affect humans. It is most often caused by bacteria called Bartonella henselae (BAR-tow-NELLuh hen-sell-A). The bacteria may infect cats and be spread to humans by bites or scratches. Cats rarely show signs of illness but humans can develop skin lesions, fever or in severe cases, systemic (whole body) infection.

What animals get cat scratch fever?

Cats, domestic and wild, are thought to be the only animals naturally infected with Bartonella henselae. Cats that have the bacteria, show no signs of disease and rarely get ill. Cats are simply carriers of the bacteria to humans. It is estimated that approximately 40% of cats have Bartonella bacteria at some point in their lives. Rare cases have been reported in dogs, horses, cattle, feral pigs, seals, whales and porpoises.

How can my animal get cat scratch fever?

The bacteria are spread from catto-cat by fleas (vector). Cats do not spread the bacteria directly to each other by bites or scratches, as they can to humans. They can acquire fleas from each other, which spreads the disease further. Feral cats are more likely to be infected than pet cats.

How does cat scratch fever affect my animal?

Cats infected with Bartonella henselae do not typically show any signs of illness.

Can I get cat scratch fever?

Yes. People can become infected with Bartonella henselae. Symptoms usually occur 3 to 10 days after being bitten, or scratched (direct contact) by an infected cat. Initially a rash, blister, or ulcer will develop at the wound site. There may be swelling of the lymph nodes. Usually the disease is self-limiting (heals on its own) in 4 to 8 weeks. For people with a weak or compromised immune system, cat scratch fever is a greater risk. In these cases, severe disease can develop into a blood infection and fever. The bacteria can infect the eye, nervous system or develop into nodular skin lesions. Complications, like heart damage or liver infection, have been reported in 5-16% of patients.

Who should I contact, if I suspect cat scratch fever?

In Animals – Cats do not show signs of disease. In Humans – Contact your physician.

How can I protect my animal from cat scratch fever?

The best way to prevent infection and spread of the disease in cats is flea control and keeping your cat indoors to avoid other cats. How can I protect myself from cat scratch fever? Avoid “rough play” with cats, especially kittens, as this could 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. Flea control may also help with prevention as this may be the source of infection in cats. Cat scratch fever is not transmitted from person-to-person.