Серопреваленца Neospora caninum код крава са репродуктивним поремећајима у Војводини / Seropevalenca Neospora caninum in cows with reproductive disorders in Vojvodina

Neospora caninum is intracellular parasitic coccidia from the phylum Apicompexa, family Sarcocystidae, responsible for abortion in cattle worldwide. Although zoonotic nature of this protozoa has not been proven, it is generally recommended that immunocompromised persons should avoid contact with the known sources of N. caninum. One of the problems that affect cattle breeding industry are great economic losses due to neosporosis-related abortions in herds of highly productive cows. The percentage of abortions ranges from 0.4% to 10.6%, although it may reach considerably higher values when the infectious agent is present in flocks. Since the disease is asymptomatic in the majority of cases, abortions in the first trimester of pregnancy may remain undetected so that the losses are often difficult to document. Depending on the gestational age of the calf, the outcome of infection may vary from the foetal resorption in early pregnancies, autolysis and mummification in the later course of the gestation, or the occurrence of stillbirths. However, cases of birth of both clinically diseased and asymptomatic, but seropositive newborns, from the infected mothers, have been recorded. In addition to the direct damage reflected in the high rate of abortions, affected farms also suffer significant economic losses due to decreased conception rates in infected cows. Also, indirect costs of veterinary services, especially those regarding expensive and toilsome diagnostic procedures, are not negligible. Finally, repeated artificial insemination increases insemination index and decreased conception rate results in prolonged service period and reduced milk production. Infected herd exhibits increased number of early calving as well as birth of non-vital calves and reduced growth in beef cattle. Serological testing, conducted on yearly basis, could contribute to the development of a control strategy of seropositivity of the cattle to N. caninum. Aim of this research was to determine seroprevalence of N. caninum in cows from the territory of Vojvodina. The study included 376 dairy cows over 24 months of age, of different breeds and divided into three groups, according to their medical history:  The first group consisted of cows with reproductive disorders  The second group consisted of cows without evident reproductive disorders  The third group consisted of cows with unknown medical history Based on these results it can be concluded that neosporosis in cows was demonstrated throughout the territory of the Vojvodina province, with overall prevalence of 15.4%. In cows with abortions and other reproductive disorders seroprevalence was 12.8% and in cows without reproductive disorders it was 18.8%. No statistically significant difference in seroprevalences between cows with and without reproductive disorders was observed. In small private holdings, seroprevalence reached 20.2% which was significantly higher compared to the 6.2% detected on large commercial farms. According to these results, the only proved risk factor for acquisition of neosporosis in cattle in Vojvodina is cattle being bred on private smallholdings, which could probably be explained by poor zoohygienic measures, free-range to semi-confined production systems and the presence of dogs, all of which are often associated with this type of farms.