Feline bartonellosis is caused by the bacteria Bartonella henselae and is the most common cause of Cat Scratch Disease in people. Most cats get this disease and transmit it to other cats from fleas. Cats with Bartonella get infected flea dirt under their nails and transmit it to people when they scratch them. Cats can also get this infection from blood transfusions. Most cats that have this disease do not show any clinical signs.
Common name: cat scratch disease, cat scratch fever
Scientific name: Bartonellosis, bartonella henselae
This disease can affect cats of all breeds, ages and sexes. However, kittens less than 1 year old, cats with flea infestations, stray or feral cats and outdoor cats are more likely to be affected.
In certain geographic areas of the United States as many as 55-80 percent of cats are estimated to be carriers of this disease.
Cats that live in warmer, more humid climates where fleas thrive are more likely to be infected.
Clinical signs (primary most to least frequent, scientific term, synonyms)
Asymptomatic: many cats do not show any signs, Lethargy (decreased energy), Fever, Enlarged lymph nodes.
Clinical signs (secondary most to least frequent, scientific term, synonyms)
Uveitis (red, cloudy eyes from inflammation), Gingivitis/Stomatitis (inflammation of the mouth and gums), Muscle pain.
Cause (scientific, common term)
Bartonella species, most commonly Bartonella henselae
Organ systems affected (most to least affected)
Lymph nodes, Mouth/gums, Eyes, Heart, Nervous system
Routine blood work and urine exam, PCR, Polymerase Chain Reaction (DNA test), Serology (antibody test), Blood cultures.
Bacterial or tick-borne infections, Viral infections (Feline Leukemia or Feline Immunodeficiency Virus), Toxoplasmosis, Stomatitis (inflammation of the mouth).
Feline Bartonellosis is caused by the bacteria Bartonella henselae and is the most common cause of Cat Scratch Disease in people. Cats are infected with this bacteria from fleas. The infected flea sheds the bacteria and cats become infected when they are scratching or grooming themselves. The bacteria can be trapped under their nails and can be passed onto people via a scratch. Cats can also harbor the bacteria in their mouth and can infect people from a bite. Kitten and cats infested with fleas are the most likely population to transmit this disease. Many cats can have this disease and do not show any signs of illness. Some cats show decreased energy, fever and enlarged lymph nodes. Recent studies suggest that chronic inflammatory diseases such as gingivitis, stomatitis, and inflammatory bowel disease may be related to Bartonella infections.
Because Bartonella is transmitted by fleas, and possibly ticks, providing proper flea control for your pet is the most important measure to take at home. Additionally, keeping pets indoors and away from other animals that may have fleas can help prevent them from getting this disease. Immunocompromised adults and children should avoid playing rough with cats, especially with kittens that may have a tendency to scratch and bite when they are playing. Any cat bites or scratches should be promptly and thoroughly washed and medical advice should be sought.
Because most cats carrying this disease do not show any signs of illness they are rarely tested for this disease. Owners that may be at higher risk for complications associated with Cat Scratch Disease (i.e. immunocompromised people) should consider testing their pets. However, they should also be aware that a variety of tests are available and all of these tests have limitations. Since many cats carry this disease but do not have any illness associated with the disease, the tests must be interpreted cautiously. General blood work and urine evaluation is usually performed. Additionally, Feline Leukemia Virus and Feline Immunodeficiency Virus testing should be performed to look for coexisting infection. Blood cultures are the most reliable way of detecting this organism. However, since the organism tends to circulate intermittently, multiple consecutive samples are often needed to make a diagnosis, which makes this test time consuming and difficult. Other methods include PCR (DNA testing) and serology (antibody detection) and can be difficult to interpret since the organism is not constantly circulating in the blood.
Treatment of this disease should be reserved for cats that appear to have Bartonella-induced disease. Serologic tests, as well as PCR and culture results, must be interpreted carefully. These animals should have a complete and in-depth medical work-up looking for other possible causes of disease. A prolonged course of antibiotics is the recommended treatment. Effectively treating this disease can be difficult and there is no evidence that antibiotics completely eliminate the Bartonella organism from infected cats.
The outcome and prognosis vary depending on concurrent underlying diseases. Occasionally, relapse or re-infection may occur after a primary course of treatment.
Lappin, Michael R. Infectious Disease-Zoonoses. In: Nelson, R.W. & Couto C.G. Small Animal Internal Medicine 3rd Edition. St. Louis: Mosby, 2003; 1312-1314.
Wood, Michael W & Birkenheuer, Adam. Bartonellosis. In: Cote, Etienne. Clinical Veterinary Advisor; Dogs and Cats. St. Louis, Mosby, 2003; 119-121.
Marisa C. Altieri, DVM
Sharon Gwaltney-Brant, DVM, PhD, DABVT, DABT