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Feline Bartonella: Beyond Cat Scratch Disease

Reviewed by Dr. Alexis Seguin, DVM, MS, DACVIM on Tuesday, August 18, 2015
Posted August 18, 2015 in Cat Diseases & Conditions A-Z

The Bartonella genus of bacteria is a group of “bugs” rapidly developing a reputation as “stealth” pathogens. There are many different species worldwide, possibly 30 or more1, and cause such diverse diseases in different animal hosts that they may be overlooked in a sick cat. They may also be confused for other problems like Lyme Disease or immune mediated hemolytic anemia (which seem more common).

Even when Bartonella is suspected of making a dog, cat or person sick, the bacteria can be hard to confirm. Repeated testing of the blood or of affected organs is often needed to diagnose bartonellosis.

Orange cat with claws outWhat makes Bartonella stealthy?
Bartonella organisms stay under the radar, and avoid being eliminated by the immune system by hiding inside circulating blood cells or blood vessels in relatively low numbers, and reproducing slowly. Infectious disease specialists believe that many vectors, such as ticks, fleas, lice or, even spiders, might be able to indirectly spread the infection between wildlife and pet animals or from animals to people. And they worry that veterinarians and physicians don’t often think about Bartonella when confronted with a sick patient.   

What is cat scratch disease?
You may have heard of cat scratch disease: a mostly self-resolving illness causing fever and swollen lymph nodes in people. It’s caused by B. henselae and acquired from the scratch or bite of an infected cat, or possibly even from happy cat kisses or licks on broken skin. It is described here by the CDC. Cat scratch disease is a common Bartonella scenario and familiar to health care professionals, but Bartonella doesn’t always present this way. There are diverse syndromes in people, dogs and cats caused by atypical infections of this species and others, some of which may be fatal.

Infection with Bartonella sp. may cause:

  • Chronic pain and fatigue syndromes (people)
  • Memory loss, headache, insomnia (people)
  • Nervous system inflammation (meningitis, encephalitis)
  • Intermittent fever
  • Chronic lymph node inflammation and swelling (lymphadenitis)
  • Chronic joint swelling (polyarthritis)
  • Liver inflammation (peliosis hepatis, granulomatous hepatitis)
  • Bone infection (osteomyelitis)
  • Inflamed heart muscle or valves (endocarditis, myocarditis)
  • Severe skin rash (vasculitis)
  • Low blood platelets, anemia , high or low white blood cells
  • Red blood cell destruction (hemolytic anemia)
  • Tumors (oncogenic transformation)

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Celeste has more than 20 years of experience in the veterinary industry and is an Internal Medical Consultant as well as a valued member of IDEXX’s Pet Health Network team since 2015.