Prevalence of borreliosis, anaplasmosis, ehrlichiosis and Dirofilaria immitis in dogs and vectors in Voronezh Reserve (Russia).

Most of the dogs studied for the prevalence of CVBD have previously received acaricidal and insecticidal treatments. In the present work, a very specific population of dogs (Group 1) that had never been treated against ticks and mosquitoes was studied. Moreover, the territory occupied by this population has also never been treated, because it is a protected area--Voronezh Natural Reserve. Canine patients from veterinary clinics (Group 2) that had been treated against VBD vectors were studied for comparison. Eighty-two dogs (Group 1) were enrolled in June, 2008. Blood samples were tested using the IDEXX SNAP(®) 4Dx(®) test. A specific heartworm antigen was detected in 12.2% samples. The seroprevalence for Anaplasma phagocytophilum was found to be 34.1%. The antibodies to Borrelia C6 peptide and to Ehrlichia canis were detected in 2.4% of the samples. Almost all dogs with infections had no clinical signs. Only 3 mixed-infected dogs showed non-specific clinical signs. During the tick season, 358 Ixodes ricinus were collected; the prevalence of Borrelia burgdorferi s.l. and Anaplasma phagocytophilum was 21.9% and 0.6%, respectively. Four hundred and forty dogs (Group 2) were studied for comparison. Antibodies to B. burgdorferi s.l. were detected only in one dog, seroprevalence for A. phagocytophilum represented 1.1%, no E. canis seropositive dogs were identified, and 8.2% dogs were found infected with Dirofilaria immitis. Fifty-six percent of dogs with dirofilariosis had clinical signs. All dogs with anaplasmosis showed specific clinical signs--fever, anemia, splenitis. Three dogs died within a few days.