Tick-borne Ehrlichiae and Rickettsiae of Dogs (2-May-2003)

Introduction Over the past several decades, tick-borne diseases caused by obligate intracellular bacteria have emerged as important threats to mammals worldwide, and have gained notoriety because of growing concern that changing climate conditions may favor vector-borne disease transmission. Canids not only become clinically affected with specific ehrlichiae and rickettsiae, but may also serve as reservoir hosts for organisms that cause disease in humans. While this article will focus on a handful of the species in the genera Ehrlichia and Rickettsia of most clinical importance to canids (Table 1), a large number of species exist, many of which have only recently emerged, and others that may still be unrecognized.