Equine protozoal myeloencephalitis: a report of two cases from Western Canada.

This study presents two cases of equine protozoal myeloencephalitis (EPM), a neurological disease in horses, observed in Western Canada. Although the exact cause wasn’t identified, the research suggests the involvement of a species from the Sarcocystis genus, rather than a species of Toxoplasma.

Introduction

• The study focuses on two reported cases of equine protozoal myeloencephalitis (EPM), a serious and often debilitating neurological disease in horses.
• This research is particularly significant as it provides insight into this disease in the geographical context of Western Canada.

Findings

• In both cases, the disease resulted in nonsuppurative myeloencephalitis, a form of inflamed brain and spinal cord without the presence of pus.
• The lesions in the diseased horses were associated with microscopic organisms that closely resembled the Toxoplasma species.
• Interestingly, the clinical signs and lesions in each horse presented differently; one primarily involved the brain while the other mainly affected the spinal cord and its surrounding membrane, known as the meninges.

Etiological Agent

• A crucial part of the study involved trying to identify the causative organism of the disease. Though the organisms found were Toxoplasma-like, it was concluded that the causative species is likely not a Toxoplasma.
• This conclusion was drawn based on more recent studies that indicate the probable involvement of a Sarcocystis species, another genus of protozoans capable of causing diseases in animals.
• However, the study was unable to provide a definitive identification of the causative organisms.

Implications

• The paper is instrumental in further understanding the manifestation and potential cause of EPM, especially considering the diversity in clinical presentation observed in the two cases.
• The findings also underline the importance of continuous research to conclusively identify the parasitic species causing this debilitating condition in horses.