Serological survey of Neospora caninum in dogs in the Czech Republic and a long-term study of dynamics of antibodies

Abstract The main aim of the present study was to establish the prevalence of antibodies against Neospora caninum dogs from the Czech Republic and to examine the dynamics of antibody titers during a long-term period. For this purpose, sera of 858 dogs were examined for the presence of anti- N. caninum antibodies using an indirect immunofluorescent antibody test (IFAT). Four groups of dogs of various origins were included in the survey: the first group (A, n  = 470) comprised dogs purchased by the Czech Army from the civilian sector throughout the Czech Republic, with 22 (4.7%) N. caninum -positive dogs, second group (B, n  = 115) represented police dogs with no seropositive animal, third group (C, n  = 195) were pet dog sera collected for veterinary clinic with 5 (2.6%) anti- N. caninum sera and the fourth group (D, n  = 78) of canine shelter dogs with the seroprevalence of 19.2%. The differences in seroprevalence were significant ( P  ≤ 0.01) between groups B and A, and between D and A. None of the serologically positive animals had clinical signs of neurological disorders. Coprological examination did not reveal any dog shedding N. caninum oocysts. The seropositivity rates for N. caninum were analyzed in relation to other data, such as age, breed and gender. Increased prevalence rates of anti- N. caninum antibodies were found in the older age strata of the dog population sample tested in the present study. We found significantly higher ( P  = 0.02) prevalence in 3–3.5-year-old dogs (11.1% of 36), as compared to 1–1.5-years-old dogs (2% of 98). A longitudinal study of antibody dynamics was carried out in 19 initially seropositive dogs over a period of 4 years. The second and third examinations revealed that antibody titers decreased in majority of positive dogs (10, 52.6%), of which in seven cases (36.8%) the titers fell to levels that are currently considered as being seronegative (titer