Large or Food Animal and Equine Medicine Commons^™

Protozoal Coinfection In Horses With Equine Protozoal Myeloencephalitis In The Eastern United States, Sarah Schale, Daniel Howe, Michelle Yeargan, Jennifer K. Morrow, Amy Graves, Amy L. Johnson

Maxwell H. Gluck Equine Research Center Faculty Publications

Background: Infection by 2 or more protozoa is linked with increased severity of disease in marine mammals with protozoan encephalitis.

Hypothesis/Objectives: To assess whether horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona also have evidence of infection with Neospora hughesi or Toxoplasma gondii. We hypothesized that horses with EPM would be more likely than horses with cervical vertebral stenotic myelopathy (CVSM) to be positive for antibodies to multiple protozoan parasites.

Animals: One hundred one horses with neurologic disease: 49 with EPM and 52 with CVSM.

Methods: Case review. Archived serum and cerebrospinal fluid (CSF) from 101 horses …

Seroepidemiology Of Sarcocystis Neurona And Neospora Hughesi Infections In Domestic Donkeys (Equus Asinus) In Durango, Mexico, Cosme Alvarado-Esquivel, Daniel K. Howe, Michelle R. Yeargan, Domingo Alvarado-Esquivel, José Alfredo Zamarripa-Barboza, Jitender P. Dubey

Maxwell H. Gluck Equine Research Center Faculty Publications

There is currently no information regarding Sarcocystis neurona and Neospora hughesi infections in donkeys in Mexico. Here, we determined the presence of antibodies against S. neurona and N. hughesi in donkeys in the northern Mexican state of Durango. Serum samples of 239 domestic donkeys (Equus asinus) were assayed for S. neurona and N. hughesi antibodies using home-made enzyme-linked immunoassays; six (2.5%) of the 239 donkeys tested seropositive for S. neurona. The seroprevalence of S. neurona infection was comparable among donkeys regardless of their origin, health status, or sex. Multivariate analysis showed that seropositivity to S. neurona was …

Analysis Of Humoral Immune Responses In Horses With Equine Protozoal Myeloencephalitis, Catherine-Jane Angwin

Theses and Dissertations--Veterinary Science

Equine protozoal myeloencephalitis (EPM), caused by the protozoan parasite Sarcocystis neurona, is one of the most important neurological diseases of horses in the Americas. While seroprevalence of S. neurona in horses is high, clinical manifestation of EPM occurs in less than 1% of infected horses. Factors governing the occurrence and severity of EPM are largely unknown, although horse immunity might play an important role in clinical outcome. We hypothesize that EPM occurs due to an aberrant immune response, which will be discernable in the equine IgG subisotypes a, b, and (T) that recognize S. neurona in infected diseased horses versus …

Equine Protozoal Myeloencephalitis: An Updated Consensus Statement With A Focus On Parasite Biology, Diagnosis, Treatment, And Prevention, S. M. Reed, M. Furr, Daniel K. Howe, A. L. Johnson, R. J. Mackay, J. K. Morrow, N. Pusterla, S. Witonsky

Veterinary Science Faculty Publications

Equine protozoal myeloencephalitis (EPM) remains an important neurologic disease of horses. There are no pathognomonic clinical signs for the disease. Affected horses can have focal or multifocal central nervous system (CNS) disease. EPM can be difficult to diagnose antemortem. It is caused by either of 2 parasites, Sarcocystis neurona and Neospora hughesi, with much less known about N. hughesi. Although risk factors such as transport stress and breed and age correlations have been identified, biologic factors such as genetic predispositions of individual animals, and parasite-specific factors such as strain differences in virulence, remain largely undetermined. This consensus statement …

Examination Of The Snsag Surface Antigen Gene Family In Sarcocystis Neurona, Ablesh Gautam

Theses and Dissertations--Veterinary Science

Sarcocystis neurona is a protozoan parasite that causes the serious neurologic disease equine protozoal myeloencephalitis (EPM). The life cycle of S. neurona progresses through multiple developmental stages that differ morphologically and molecularly. The S. neurona merozoite surface is covered by multiple related proteins, which are orthologous to the surface antigen (SAG) gene family of Toxoplasma gondii. The SAG surface antigens in T. gondii and another related parasite Neospora caninum are life cycle stage-specific and seem necessary for parasite transmission and persistence of infection. The present research was conducted to explore the gene family of SnSAGs in S. …