A Serological Survey of Neospora caninum Infection in Urban and Rural Dogs in Ahvaz District, Southwest of Iran.

Dogs are important in the epidemiology of Neospora caninum because they act as definitive hosts, shedding oocysts in the environment. The aim of the present survey was to evaluate the serological prevalence of Neospora caninum infection in urban and rural dogs in Ahvaz district, southwest of Iran. In this study, blood samples were taken from 100 rural dogs and 50 urban dogs. The dogs were categorized into two age groups (i.e., ≤ 3 and > 3 years). Neospora agglutination test (NAT) was performed for the detection of infection. Among 150 samples, 30 (20%) showed infection in 1:50 to 1:800 dilutions by NAT (confidence interval 95%: 13.60-26.40). The antibody titers were as follows: 1:50 (n=1), 1:100 (n=14), 1:200 (n=3), 1:400 (n=10) and 1:800 (n=2). The highest serum dilution was 1:100 in 46.67% of the infected dogs and the lowest serum dilution was 1:50 in 3.33% of them. The obtained results showed a significant difference in seroprevalence between urban (10%) and rural (25%) dogs (P=0.03). Although the seroprevalence was higher in dogs above three years of age (23.33%) than below three years (17.78%), there was not a significant difference among different age groups in this regard (P>0.05). The possibility of infection in dogs above the age of three years was 1.3 more than those below three years of age (confidence interval 95%: 0.58-2.9). It can be concluded that a relatively considerable percentage of dogs in Ahvaz district are infected with N. caninum. These infected dogs can play an important role in the transmission of neosporosis to other animals.