The brown dog tick (Rhipicephalus sanguineus) is an important pest of dogs worldwide that occasionally will feed on humans. This tick is unique in that it can develop indoor populations, often reaching high levels. This tick is an important vector for several dog pathogens, including those causing canine ehrlichiosis and babesiosis. Recently, this tick has been shown capable of transmitting Rocky Mountain spotted fever in the southwestern US and nearby parts of Mexico.