Neospora caninum - Associated Abortions in Slo¬vak Dairy Farm

Neospora caninum is considered one of the major causes of repeated abortions in livestock. This study aimed to determine the seropositivity to N. caninum using indi­rect ELISA and the influence of the infection on the occurrence of abortions in selected dairy herd in Slovakia. Blood samples were obtained from 490 cattle over a period of two years and were tested for N. caninum antibodies using indirect ELISA. 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 seropositive mothers was 2.1 times higher than in progenies of seronega­tive dams. Molecular 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. Study revealed significant correlation between the presence of specific antibodies and the occurrence of abortions, the risk of abor­tion in seropositive animals was 3.8 times higher than in seronegative ones. Incorrect farm management contributed to spread and circulation of neosporosis in entire dairy herd what could significantly impair the reproduction and economic parameters of breeding.