Neospora caninum, potential cause of abortions in dairy cows: The current serological follow-up in Slovakia

Neosporosis is considered to be a contributing risk factor for abortions in dairy cows and other farm animals and has negative economic impact on their breeding. In respect of the rapid spread of neosporosis in herds throughout the world, our aim was to detect the prevalence of anti-Neospora antibodies in cows post-abortion (PA) (PA Group n = 716) and in cows without any reproduction problems (Control Group n = 247) on large breeding farms from Eastern Slovakia. The overall mean seropositivity in PA Group (20.1%) was significantly higher (p < 0.0001) in comparison with the Control Group (2.3%), and this demonstrates the causal dependency of abortions on neosporosis. On farms from south-east region, 15.6% of cows were seropositive on average ranging from 7.8% to 25.8% in different districts. In the northern region, significantly (p = 0.0002) higher 26.2% mean seropositivity was detected. The seroprevalence in different districts ranged from 2.9% to 39.4%. In the PA Group a high seropositivity to infectious bovine rhinotracheitis (41.5%) and sporadic occurrence of Q-fever, leptospirosis and chlamydiosis was also detected. From 11 Toxoplasma-seropositive cows, only one animal was simultaneously positive to Neospora. The relatively high prevalence rate in cows warrants the attention and a need of surveillance in Slovak herds. A better knowledge of epidemiology of this etiological agent and the mechanisms of its transmission may help in the introduction of more effective preventive and control measures.