Domestic animals and wildlife represent a large reservoir for bartonellae, at least eight species or subspecies of which have been reported to cause zoonotic infections. In addition, numerous orphan clinical syndromes are now being attributed to Bartonella henselae infection. Many mammalian species, including cats, dogs, rodents and ruminants are the main bartonellae reservoirs. Cats are the main reservoir for B. henselae. It appears that domestic dogs, at least in non tropical regions, are more likely to be accidental hosts than reservoirs, and constitute excellent sentinels for human infections. Bartonellae are vector-borne bacteria. The mode of B. henselae transmission by cat fleas is now better understood, but new potential vectors have recently been identified, including ticks and biting flies. This articles summarizes current knowledge of the etiology, new clinical features and epidemiological characteristics of these emerging zoonoses.