A serological survey on Borrelia burgdorferi infection among companion dogs in Ahvaz district, southwestern Iran

Canine Lyme borreliosis is one of the most common tick-transmitted diseases in the world. The infection is caused by spirochetal bacteria from the genus Borrelia burgdorferi. The principal vectors are various species of slow-feeding hard ticks of the Ixodes complex. Dogs are the most infected animals among the pets. The status of infection due to Borrelia in dogs remains unknown in many areas of Iran. Few studies have been reported on the distribution of this disease in the Iran dog’s population, so the aim of this survey was to evaluate the seroprevalence of Borrelia infection in companion dogs in Ahvaz district (southwestern Iran), from October 2011 to August 2013. In the present survey, a total of 168 companion dogs with different ages were examined for serum antibody detection against B. burgdorferi by immunochromatography assay (ICA) (catalog No. RB 21–22). The dogs were selected between referred cases to Veterinary Hospital of Shahid Chamran University of Ahvaz, southwestern Iran. They were classified according to age, sex, season, and region. The studied dogs were divided based on age into three groups (group 1, <1 year; group 2, 1–5 years; and group 3, >5 years) and based on area into five regions (north, east, west, south, and central). The results were analyzed by using chi-square analysis, Fisher’s exact test, and Z test. Sixteen out of 168 serum samples (9.52 %) had antibodies against B. burgdorferi (95 % CI for proportion, 5.1–13.9 %). Prevalence was significantly higher in adult dogs above 5 years (19.40 %; 13 out of 67) compared with dogs between 1 and 5 years (3.77 %; 2 out of 53) and less than 1 year (2.08 %; 1 out of 48) (P < 0.05). Prevalence was higher in male dogs (10.53 %; 10 out of 95) than in female dogs (8.22 %; 6 out of 73), in the season of summer (11.90 %; 5 out of 42) and west region (11.11 %; 4 out of 36), but the difference was not significant between the prevalence of infection relative to host gender, season, and region (P > 0.05). The results of the present study provide useful information on the epidemiology of Lyme diseases in this area, which until now was not studied. Our results emphasize the presence of tick-borne diseases and the need for public health interventions.