Reactivity against Sarcocystis neurona and Neospora by serum antibodies in healthy French horses from two farms with previous equine protozoal myeloencephalitis-like cases.

The study investigates the presence of antibodies against Sarcocystis neurona and Neospora, pathogens causing a prevalent neurological disease in horses, in healthy horses from French farms that have reported cases of this disease in the past.

Background

• The research focuses on two pathogens, Sarcocystis neurona and Neospora, which are recognized as the primary causes of Equine Protozoal Myeloencephalitis (EPM), a widespread neurological illness in horses.
• The disease is more commonly encountered in the Americas. However, recent reports show cases in Normandy, France, where horses had antibodies reacting with an S. neurona peptide.

Methodology

• An agglutination assay was used to detect antibodies in 18 out of 50 healthy horses from two French farms that had previously reported EPM-like cases. This assay helps determine the presence of antibodies in the blood serum that react with the S. neurona merozoites.
• The antibody titers in these horses ranged from 50 to 500, with higher figures found in older animals.
• Particularly, four out of six horses that had either traveled to, or stayed in, the US showed higher antibody titers over 50, compared to horses that did not travel out of France or stayed in another European country.

Findings

• No correlation was found between the presence of antibodies against S. neurona and Neospora in the horses.
• The presence of anti-S. neurona antibodies even in clinically healthy horses on farms with previously occurred EPM-like cases necessitates further studies.

Implications

• The findings emphasize the necessity for more in-depth investigations regarding the significance of S. neurona antibodies in both clinically healthy and diseased horses in Europe.
• It is crucial to identify the immunizing parasites causing these reactions and their specific hosts.
• Understanding the cause and effect relationship of these antibodies could potentially help in developing effective preventive measures.