The cosmopolitan Brown Dog Tick (R. 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 R. sanguineus 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. (Lord 2001).
As a 3-host tick, R. sanguineus drops off its host between developmental stages (larva, nymph, and adult), although if few hosts are available it is likely to re-attach to the same individual. After feeding on a host for around a week, an adult female drops off and finds a protected site while her eggs develop. She may begin laying eggs in around four days and may continue for two weeks, after which she dies. A well-fed adult female can lay up to 5,000 eggs. Larvae hatch two to five weeks later and search out a host. Once on a host, a larva feeds for three to seven days, then drops off and take about two weeks to develop into a nymph. After finding a host, a nymph feeds for five to ten days before dropping off and taking about two weeks to develop into an adult. As adults, males feed for only short periods. The entire life cycle can be completed in just over two months, but if hosts are difficult to locate or temperature is low it takes longer. These ticks can live as long as three to five months in each stage without feeding. (Lord 2001).
In the United States, R. sanguineus can transmit canine erlichiosis (caused by Ehrlichia canis) and canine babesia (caused by Babesia canis) to dogs. In parts of Europe, Asia, and Africa, these ticks transmit Rickettsia conorii, which causes boutonneuse fever. Rhipicephalus sanguineus is not known to transmit Lyme disease. (Lord 2001).