Tick Fever Is caused by a tiny organism called rickettsia, which is a type of bacteria that has evolved to behave more like a virus, in that it can actually take over living cells and grow inside them.

The 2 most common forms of rickettsia causing Ehrlichiosis in dogs and their wild wolf cousins are Ehrlichia canis (which is transmitted by the Brown Dog tick, and is by far the most prevalent) and Ehrlichia ewingii (transmitted by the Lone Star tick).