Is Bartonella a player in feline stomatitis? (Proceedings)

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Is Bartonella a player in feline stomatitis? (Proceedings)

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Oct 01, 2008

Objectives

  • Update on Bartonella spp as a "rediscovered" etiologic agent in human, canine and feline disease
  • Discuss etiology and epidemiology of Bartonella spp in our feline population
  • Provide results of a study evaluating the association between feline stomatitis and bartonellosis

Key Points

  • Bartonella spp. are being recognized as re-emerging human pathogens
  • The zoonotic potential of Bartonella spp. makes this an important concern for cat owners
  • The majority of cats with bartonellosis are asymptomatic
  • Bartonella spp. have been the proposed etiologic agents resulting in clinical signs in cats, including uveitis, endocarditis, gingivitis, stomatitis, and lymphadenopathy.
  • The high prevalence rate of Bartonella positive in healthy cats makes it difficult to determine cause and effect of disease relative to Bartonella status
  • Preliminary results suggest that there is not an association between Bartonella and stomatitis
  • Other infectious or immune causes of stomatitis should be considered prior to specific anti-Bartonella therapy

Background

Bartonellosis is an important emerging disease in humans and has been recognized to cause clinical disease in several other species, including dogs. Bartonella henselae is the primary etiologic agent in Cat Scratch Disease, which causes fever and lymphadenopathy in humans. Bartonella spp. can result in more serious pathology in humans including bacillary angiomatosis and bacillary peliosis, especially in immunosuppressed individuals. For these reasons, Bartonella spp. pose a zoonotic risk. Cats are often asymptomatic carriers for B. henselae and B. clarridgeiae. Whether these agents, or other Bartonella spp., cause clinical disease in cats is currently being investigated.

Epidemiology

Bartonella spp. are transmitted primarily via arthropod vectors, which vary depending on the species. Fleas are thought to be the primary vector in cats, which is supported by the higher prevalence of Bartonella positive cats from flea regions. Cats may clear the organism, but may also become asymptomatic carriers with intermittent episodes of bacteremia. Seroprevalence rates range from 5% - 90% of cats, depending on the region of interest.

Bartonella-Induced Disease

Chronic, intracellular bacteria can induce over-exuberant host responses and so the supposition that Bartonella spp., which may not always be cleared by the feline host, could induce the lymphocytic-plasmacytic lesions indicative of stomatitis and other immune-reactive diseases. Several studies have evaluated the correlation between Bartonella spp and hemolytic anemia, uveitis and endocarditis. The majority of studies have either shown no significant difference between healthy cat populations and affected cats with regard to Bartonella antibody titers and amplification of organism DNA using PCR or a single case reports of disease association. A case report of a cat with vegetative endocarditis identified B. henselae via PCR performed on the affected aortic valve, but blood cultures from the cat were negative. Similarly, the aqueous humour of client-owned cats with uveitis, cats experimentally infected with Bartonella spp and healthy shelter cats with normal ocular exams was evaluated via IgG titers and PCR. Some of the cats with uveitis and those experimentally infected with Bartonella spp showed evidence of intraocular production of antibodies as well as organismal DNA in 3 cats out of 24 with uveitis, while only one of the 49 healthy cats had Bartonella DNA present in the aqueous humour without IgG production. There was no statistical difference among the groups, but numbers in groups may have been too small to detect such differences. Therefore, it is possible that some cases of uveitis may be caused by Bartonella spp.