Brown dog tick. Light micrograph (LM) of a brown dog tick (Rhipicephalus sanguineus). This tick is one of the most important vectors of diseases in dogs worldwide. In the United States it is a vector of canine ehrlichiosis (Ehrlichia canis) and canine babesiosis (Babesia canis). Symptoms of canine ehrlichiosis include lameness and fever; those for babesiosis include fever, anorexia and anemia. In parts of Europe, Asia and Africa, it is a vector of Rickettsia conorii, known locally as Mediterranean spotted fever, boutonneuse fever, or tick typhus. Magnification: x10 when printed at 10cm wide.