SEIZURE ACTIVITY ASSOCIATED WITH EQUINE PROTOZOAL MYELOENCEPHALITIS

Equine protozoal myeloencephalitis (EPM) has been reported to produce numerous syndromes of central nervous system dysfunction; however, sei zure activity has not been documented previously as a sequela to EPM. We documented seizure activity as the predominant clinical sign in thr ee EPM cases in which the diagnosis was established by immunoblot anal ysis of serum and cerebrospinal fluid for Sarcocystis neurona specific IgG, response to therapy, and/or postmortem examination. Electroencep halography (EEG) was used to establish a neurophysiologic basis for th e seizure activity in all cases, and the anatomic basis for the EEG ab normalities was documented in the two cases in which a postmortem was performed. By considering EPM as a differential diagnosis for equine s eizure activity, veterinarians may establish an etiologic diagnosis in cases which previously would have remained undiagnosed. Early institu tion of antiprotozoal therapy may result in recovery and return to ath letic performance, as in Case 1.