Cat Scratch Disease (Bartonella henselae Infection)
What is cat scratch disease?
Cat scratch disease (CSD) is a bacterial disease in people caused by Bartonella henselae. Most
of the over 22,000 people infected each year with CSD have been bitten or scratched by a cat
and developed a mild infection at the point of injury. Over 2,000 people/year are infected and
require hospitalization. Lymph nodes, especially those around the head, neck, and upper limbs,
become swollen. Additionally, a person with CSD may experience fever, headache, fatigue, and
a poor appetite. Children may develop an infectious mononucleosis like syndrome. Rare
complications of B. henselae infection are bacillary angiomatosis and Parinaud’s oculoglandular
syndrome. Antibiotics can shorten the clinical course of the CSD, which usually lasts 6 to 8
weeks if untreated.
Can my cat transmit Bartonella henselae to me?
Sometimes, yes, cats can spread B. henselae to people. Most people get CSD from cat bites and
scratches. Kittens are more likely to be infected and to pass the bacterium to people. About
40% of cats carry B. henselae at some time in their lives. Cats that carry B. henselae may not
show any signs of illness; therefore, you cannot tell which cats can spread the disease to you.
People with immunocompromised conditions, such as those undergoing immunosuppressive
treatments for cancer, organ transplant patients, and people with HIV/AIDS, are more likely
than others to have severe complications of CSD. However, more people with healthy immunes
systems are infected with Bartonella sp. than immunosuppressed ones. Although B. henselae
has been found in fleas and ticks, so far there is no evidence that a bite from an infected flea or
tick can give you CSD.
How can I reduce my risk of getting cat scratch disease from my 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.
Control fleas and ticks 100%, which means all in-contact pets are put on effective control
products such as Revolution or Frontline Plus monthly treatment and preventatives. If the pet’s
environment is visibly infested then applying insect growth regulators (IGR) with active
ingredients such as Precor or Nylar will help the problem in a quicker fashion. Most of the IGR’s
are available in combination with adult flea and tick killers. Be sure to read instructions carefully
and keep your cats out of the area until all products have dried.
If you develop an infection with pus and pronounced swelling where you were scratched or
bitten by a cat, or develop symptoms, including fever, headache, swollen lymph nodes, and
fatigue, contact your physician.
How do I know if my cat is infected?
While many cats do not have outward signs of disease, clinical signs can include chronic gum
disease (gingivitis), upper respiratory disease (rhinitis and sinusitis), eye infections
(conjunctivitis), chronic vomiting and diarrhea, as well as enlarged lymph nodes and fevers of
unknown origin. Your veterinarian can test your cat by sending a drop of blood to the National
Veterinary Laboratory. A Western Blot (FeBart)Â test will determine if your cat has been exposed
to Bartonella bacteria.