Background: Neospora caninum is considered one of the major causes of repeated abortions in livestock. This study aimed to determine the seropositivity to N. cani-num using indirect ELISA and the influence of the infection on the occurrence of abortions in selected dairy herd in Slovakia. Method:Blood samples were obtained from 490 cattle over a period of two years and were tested for N. caninum antibodies using indirect ELISA. Results:The presence of specific antibodies in the herd was detected in 118 (24.1%) cows. According to selected groups; 117 (41.0%) cows with a history of abortion, 65 (43.3%) heifers and 223 (2.2%) cows without abortions were tested positive to Neospora. Vertical transmission of N. caninum dominated in examined herd and the relative risk (RR) of dam-daughter seropositivity in progenies of sero-positive mothers was 2.1 times higher than in progenies of seronegative dams. Mo-lecular analyses of aborted foetuses of seropositive mothers showed the presence of Neospora DNA. However, 23 (28.1%) of heifers born to seronegative cows were seropositive, indicating also the postnatal transmission of the infection from the environment. Conclusion:Study revealed significant correlation between the presence of specif-ic antibodies and the occurrence of abortions, the risk of abortion in seropositive animals was 3.8 times higher than in seronegative ones. Incorrect farm manage-ment contributed to spread and circulation of neosporosis in entire dairy herd what could significantly impair the reproduction and economic parameters of breeding. |