Feline Bartonellosis Study Guide

Overview and Clinical Importance

Bartonellosis is an important emerging zoonotic infection caused by bacteria of the genus Bartonella. Cats serve as the primary reservoir host for Bartonella henselae, the causative agent of cat scratch disease (CSD) in humans. While most infected cats remain asymptomatic carriers with chronic bacteremia lasting months to years, bartonellosis can occasionally cause clinical disease including endocarditis, uveitis, fever, and lymphadenopathy. Understanding feline bartonellosis is essential for the NAVLE due to its zoonotic significance and the role veterinarians play in public health prevention.

The prevalence of B. henselae bacteremia in cats ranges from 25-40% worldwide, with higher rates in warm, humid climates where flea infestations are more common. Seroprevalence varies regionally, from 6% in Illinois to 33% in Florida. Kittens and shelter/stray cats demonstrate higher infection rates than adult owned cats.

Etiology

Causative Agent

Bartonella species are small (0.3-0.6 by 1.0-1.7 micrometers), fastidious, facultative intracellular, Gram-negative bacteria belonging to the family Bartonellaceae. They are pleomorphic, non-capsulated, non-sporing rods that invade and replicate within erythrocytes and vascular endothelial cells. The bacteria are highly hemin-dependent and require enriched blood-containing media for culture, with primary isolation requiring 5-45 days of incubation.