Ehrlichiosis is an infection of the group of Vector Borne Diseases (VBD), caused by different echrlichia species (spp). Ehrlichiae are primarily recognized as causers of animal diseases, later as human diseases—Humane Monocytic (HME) and Humane Granulocytic (HGE) ehrlichiosis. The dogs, cats and rodents have natural reservoirs of ehrlichial agents. Ehcrlichiae are spread to human’s trough, the bites of infected ticks, sometimes resulting from contact with animals, possible to the transfusion. In period from 2008 to 2013, we analyzed 250 patients suspect of VBD. On examination, there were included clinical, laboratory and epidemiological methods. The confirmation of Ehrlichia canis was in serum of 64 patients, thanks to Indirect Immune fluorescent Assay (IIF). The other laboratory and serological methods (Elisa, IIF, and Western blood) are utilized for differential diagnosis, and detection of co-infective forms of diseases. Ehrlichia canis infection has been reported in humans as a cause of serious illnesses characterized by non specific symptoms: fever, headache, musculoskeletal pain, enlarged liver, neurological, hematological dysfunction. Co-infections with E. canis due to causers of different VBD have been documented in humans. In 53 cases, we detected co-infective participation of E. canis with Rickettsia conorii in 24 cases, Coxiella burneti in 6, and Borrelia burgdorferi in 23 cases. The preferred drug for both human ehrlichiosis is doxycycline, except children to 8 years, pregnant females. Ehrlichiosis is a difficult infectious disease to diagnose and prognose because of dominant non specific symptoms and co-infections.