Fatal case of endocarditis associated with Bartonella henselae type I infection in a domestic cat.

We report the first feline case of Bartonella henselae endocarditis. Despite negative blood cultures, the cat had high Bartonella antibody titers and B. henselae type I DNA was detected in the damaged aortic valve. Microscopic examination of the valve revealed endocarditis with small silver positive coccoid structures in endothelial cells.