Risk Factors for Occurrence of Anti-Neospora spp. Antibodies in Horses From Alagoas, Brazil

• Equine neosporosis Study of infection by Neospora spp. in horses in Brazil.
• Risk factors identified for horses.

The aim of the present study was to investigate the frequency of Neospora spp. infection, as well as its associated risk factors, in horses in the state of Alagoas, Brazil. In total, 427 samples from 36 properties in 23 districts, covering three mesoregions, were studied. An immunofluorescence assay was used to quantify anti-Neospora caninum immunoglobulin G antibodies, and risk factors were assessed through investigative questionnaires that focused on the productive, reproductive, and sanitary management of herds. Data from the questionnaires were evaluated by two statistical analyses. The total frequency of anti-Neospora spp. antibodies found was 18% (95% confidence interval [95% CI]: 14.4–22.1). At least one seropositive horse was found in 72.2% of the farms evaluated (26 of 36). The following risk factors were associated with infection: the access of other species to the horses' water source (P = .017; odds ratio [OR] = 1.84; 95% CI: 1.11–3.04); no to consume hay (P = .000; OR = 3.33; 95% CI: 1.87–5.94); the informal purchase of animals (P = .000; OR = 8.43; 95% CI: 3.06–23.16); and an absence of quarantine management (P = .000; OR = 8.70; 95% CI: 3.10–24.39). The results of the present study show that horses in the state of Alagoas are at risk for Neospora spp. infection, and care should be implemented based on identified risk factors to prevent infection in horses.