Canine and Feline Anaplasmosis and Ehrlichiosis

Although tick-borne pathogens are of tremendous historical importance to both veterinary and human medicine, recent events emphasize an expanding role for newly discovered, as well as previously recognized tick-transmitted organisms, as a cause of animal and human suffering. One of the most important new developments related to anaplasmosis and ehrlichiosis is the realization that a given mammalian species can be infected simultaneously or sequentially by several Ehrlichia species. 1 As an example, both dogs and people can be infected with Ehrlichia chaffeensis, Ehrlichia canis, Ehrlichia ewingii and Anaplasma phagocytophilium (see reclassification below).