Immunity, Pathophysiology, and Diagnosis of Equine Protozoal Myeloencephalitis

Our understanding of the pathophysiology of equine protozoal myeloencephalitis (EPM) remains incomplete, yet the development of clinical models, engineered mice, and molecular techniques have contributed markedly to our knowledge of this illness. Research confirms that the most important mediator of immunity to EPM is interferon-gamma, while the humoral immune system also contributes via inactivation of specific protozoal surface proteins. Diagnosis of EPM remains a clinical challenge, yet careful consideration of the clinical examination, coupled with ancillary diagnostic tests such as the cerebrospinal fluid evaluation, and various immunodiagnostic tests (Western blot, indirect fluorescent antibody) provide support for a clinical diagnosis.