seroprevalence of toxoplasma gondii and neospora spp. infections in arab horses, southwest of iran

background because of the economic importance of the arab race horses and also the role of toxoplasma gondii and neospora spp. in abortion and reproductive failure of these animals, we decided to perform this study. objectives we designed this study to investigate the seroprevalence of anti-toxoplasma gondii and anti-neospora spp. antibodies in arab horses from 12 cities of khuzestan province in southwest of iran. materials and methods from october 2009 to march 2011, a total of 235 blood samples were collected from jugular veins of arab horses of different ages and genders from 12 cities of khuzestan province. all the sera were tested for anti-toxoplasma antibodies using the modified agglutination test (mat) and the existence of anti-neospora antibodies were tested using n-mat for neospora spp. results according to the mat results, antibodies to t. gondii were found in 114 (48.5%) of 235 sera with titers of 1:20 in 84, 1:40 in 19, 1:80 in four, 1:160 in four, and 1:320 in three horses. according to the n-mat results, antibodies to neospora spp. were found in 47 (20%) of 235 sera with titers of 1:40 in 39, 1:80 in five, and 1:160 in three horses. we did not observe any statistically significant differences regarding age groups and genders between seropositive and seronegative horses for neospora spp. using chi-square (χ2) test, but it seemed that anti-toxoplasma antibodies were more prevalent in older horses (≥ 10 years old). conclusions the results indicated that arab horses are exposed to these parasites in southwest of iran. further research is required to determine the genomic structures of these parasites in arab horses in southwest of iran.