EFFECT OF EQUINE PROTOZOAL MYELOENCEPHALITIS (EPM) AND/OR TREATMENT WITH DARAPRIM® AND TRIBRISSEM® ON SPERM MOTILITY AND CONCENTRATION OF AN ARABIAN STALLION

Abstract

Equine Protozoal Myeloencephalitis (EPM) is a neurological pathology caused by the migration of the protozoan Sarcocystis neurona (falcatula) into the Central Nervous System (CNS). EPM is often a progressively debilitating disease affecting the CNS of horses. Clinical signs range from acute to chronic, with an insidious onset of focal or multifocal signs of neurological disease involving the brain and/or spinal cord, resulting in diffuse and asymmetrical involvement of the CNS. Early signs of the disease, such as frequent stumbling and flapping of the limbs, can be easily confused with lameness. Horses affected with EPM usually experience a gradual progression in the severity and variety of clinical signs, including ataxia. Treatment includes administration of trimethoprim-sulfamethoxazole or sulfadiazine and pyrimethamine (TMS-Pyr). In equine breeding, empirical evidence suggests the possibility of adverse effects of TMS-Pyr on semen quality, sexual behavior and ejaculatory function. The objective of this report was to demonstrate and evaluate the effect of the pathology/treatment on seminal characteristics, sexual behavior and ejaculatory function of a stallion affected by MEP.