Horses seropositive for Toxoplasma gondii, Sarcocystis spp. and Neospora spp.: Possible risk factors for infection in Brazil.

This study conducted in Brazil explores the occurrence and potential risk factors for parasitic diseases in horses, including Toxoplasma gondii, Neospora spp., and Sarcocystis spp. infections. The results indicate a significant prevalence of these diseases among the studied horse population, with older animals showing a higher prevalence of Neospora spp. infection.

Research Purpose and Methodology

• The study aimed to investigate the presence of antibodies against Toxoplasma gondii, Neospora spp., and Sarcocystis spp. in horses, and identify any potential risk factors for acquiring these diseases. These parasitic diseases are often asymptomatic but may cause pathological changes in the host.
• A total of 174 horses, 90 males and 84 females within an age range of two to 20 years, were examined for this study.
• Blood samples were acquired from these horses and stored without an anticoagulant to derive the serum.
• The serum was subjected to indirect immunofluorescence assay (IFA) tests to detect the presence of antibodies against the parasites.

Key Findings

• Results from the IFA tests indicated that 41.37% of the horses had Sarcocystis spp., 32.18% had T. gondii, and 48.27% had Neospora spp.
• Out of the total number of horses studied, 81 showed a simple infection (with just one of these parasites), while 61 horses had mixed infections with two or three of these parasites. Only 32 horses did not have antibodies to any of these pathogens, indicating no exposure to the parasites.
• No identifiable risk factors were found for Sarcocystis spp. and T. gondii infections.
• There was a significant correlation between the age of the horses and infection by Neospora spp. Older horses showed a higher prevalence of this infection.
• Despite the high prevalence of these parasites, all of the horses studied were asymptomatic, with no reproductive, neurological, or locomotor problems indicating infection.

Conclusion

• The findings of this study suggest that T. gondii and Neospora spp. significantly affect horses in Southern Brazil, despite not displaying any symptoms. The researchers point to the population density of horses and the interaction between many different animal species in the area as potential factors for the high rate of parasitic infections.
• Although these infections are often asymptomatic, the underlying damage they may cause to the host animals warrants further investigation and underscores the need for preventative measures.