Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 12 3 2017 09 17 408 412 Morteza HOSSEININEJAD Dept. of Clinical Sciences, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord, Iran Mohammadreza MAHZOUNIEH Dept. of Pathobiology, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord, Iran Naser SHAMS ESFANDABADI Dept. of Clinical Sciences, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord, Iran 2017 09 17 2017 09 17 Background: This study aimed to reveal the serological prevalence of Neospora caninum in large dairy farms in Isfahan Province, central Iran. Methods: Serum samples were collected from 1500 cattle living in four large dairy farms in Isfahan Province, Iran during 2014-2015 and examined for anti N. caninum IgG antibodies.  Overall, 113 serum samples were also collected from the dogs living in these areas; suspecting to be risk factors for this infection. All the serum samples were investigated to find IgG antibodies by using ELISA. Dogs' sera were also analyzed by indirect fluorescent antibody test. Results: Totally, 395 out of 1500 bovine samples (26.33%) were positive for N. caninum: 34%, 21.61%, 23.03% and 29.01% in four investigated clusters (farms). Infection rate was significantly more in cows with the history of abortion. The infection rate in dogs was 17.69%: (20 out of 113). Conclusion: The results show a high seroprevalence of the infection and possibly the role of the dogs in horizontal transmission of the infection.  https://ijpa.tums.ac.ir/index.php/ijpa/article/view/1772 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/1772/763