Rickettsiae (bacteria of the genus Rickettsia) are globally occurring organisms that are found in many ticks, fleas, mites and lice and for which these serve as vectors (carriers).
In humans (endemic in Mediterranean countries, Eastern Europe, the tropics and North America) they cause a whole range of diseases with different clinical pictures, which are medically summarised in the group of rickettsioses. Examples include spotted fever (syn. typhus exanthematicus), Wolhynian fever (trench fever), rickettsial pox, Brill-Zinsser disease, Boutonneuse fever (Mediterranean tick spotted fever) and Rocky Mountain spotted fever.
In dogs, signs of an infection with Rickettsia may include fever, lack of appetite, depression, loss of stamina, lameness, and coughing.