Background: Ehrlichiosis in dogs is a vector borne disease caused by Ehrlichia canis, from the Anaplasmataceae family, capable of causing multisystemic disorders. Following an incubation period of 8-20 days, acute, subclinical and chronic forms of the disease may develop and affected dogs frequently showed hemorrhage, lymphadenopahty, splenomegaly, hepatomegaly, along with cardiac/renal disorders and myelosupression. Most of the untreated dogs spontaneously recover form the acute phase and enters the subclinical phase, in which some of them may develop chronic phase characterized by bone marrow aplasia. Ehrlichial organisms are commonly susceptible to tetracycline derivatives, and doxycycline is probably most commonly used for treatment of the infection. Doxycycline may be quite effective for clearing parasitemia in acute E. canis infection. Clinical recovery may be observed within 2-3 days, besides treatment should be continued for 3 weeks, as some cases may remain carriers even if short treatment protocole is administered. Most dogs infected with CME usually recover from the acute and subclinical phases when treated with doxycycline or other tetracyclines. Some dogs enter the chronic phase of the disease for which the prognosis is grave. The purpose of the present study was to report the presence of E. canis infection in dogs in Aydin, with a special reference to the efficacy of combined doxycycline and chloroquine therapy.