Case report of equine protozoal myeloencephalitis (EPM) in Argentina
DOI:
https://doi.org/10.24215/15142590e035Keywords:
Sarcocystis neurona, EPM, Diagnosis, ArgentinaAbstract
Equine protozoal myeloencephalitis (EPM) is mainly caused by Sarcocystis neurona and generates significant
economic losses. In Argentina, antibodies to this protozoan have been detected but no clinical cases have been reported. A 12year old mare, from Buenos Aires Province, presented asynchronous walking and bilateral stringhalt. The animal was treated with phenytoin, vitamin B1, nonsteroid antiinflammatory drugs and subsequent tenectomy. Clinical outcome progressed to depression, facial paralysis, atrophy of the muscles of the back, loin and pelvic limbs, dysmetria and gait instability, generalized tremors and tetraparesis. Euthanasia was decided based on clinical progression and lack of response to treatment. Microscopic lesions were observed in thalamus, metencephalon and spinal cord, and consisted in small hemorrhagic multiple foci and small foci of chronic inflammation. Immunohistochemical analysis revealed the presence of intracellular S. neurona meronts and free merozoites in brain and spinal cord samples. The PCR-RFLP analysis showed a specific S. neurona restriction pattern in brain samples. Previous detection of antibodies to S. neurona in horses, the abundance of opossums in the region and the specific confirmation in this case, suggest that the disease may be widespread in Argentina. This is the first EPM case
report in Argentina, confirmed by histopathologic, immunohistochemical and molecular studies.
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