Seroepidemiological survey of Theileria equi and Babesia caballi in horses from a rural and from urban areas of Paraná State, southern Brazil

The objective of this study was to evaluate the seroepidemiological data of Babesia caballi and Theileria equi in horses from a rural settlement and carthorses from urban areas of Paraná State, southern Brazil. A total of 198 horses, including 32 from the rural settlement and 166 carthorses from Colombo (n = 48), Pinhais (n = 76), Londrina (n = 24), and Curitiba city (n = 18) was sampled and tested using a commercial competitive inhibition ELISA (cELISA) test. Out of the 198 horses, 193 (97.5%) were seropositive for at least one piroplasm species. Antibodies to T. equi were detected in 155/198 horses (78.3%), antibodies to B. caballi were detected in 137/198 horses (69.2%), and antibodies to both were detected in 99/198 (50.0%) horses. Horses living in the rural settlement and Colombo were more likely to be seropositive to T. equi than those in Curitiba (p < 0.05). Horses older than 5 years were more likely to be seropositive for T. equi than those younger than 5 years (p < 0.05). No significant association was found between gender or the presence of ticks and seropositivity to T. equi (p > 0.05). In conclusion, the high seroprevalences to B. caballi and T. equi observed in this study emphasize that active surveillance programs are critical for monitoring animal health status, particularly because carthorses may act as urban disseminators of these piroplasms.