The Brown Dog Tick (Rhipicephalus sanguineus) can transmit the Rickettsia bacteria that cause Rocky Mountain spotted fever and boutonneuse fever. This small, elongated, red-brown tick is unusual in that it can complete its entire life cycle indoors, facilitating its spread around the world. Although Brown Dog Ticks will feed on a wide variety of mammals (including humans), in the United States dogs are the preferred host and appear to be required to develop large infestations.