Changes

====Description====

====Description====

A progressive, infectious,<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''', third edition, SUDZ Publishing, 245-250.</ref>neurological disease of horses, endemic in the USA<ref name="EPM8">Gray, L.C, Magdesian, K.G, Sturges, B.K, Madigan, J.E (2001) Suspected protozoal myeloencephalitis in a two-month-old colt.  ''Vet Record'', 149:269-273.</ref> and only encountered elsewhere in imported equids.<ref name="EPM3">Vatistas, N, Mayhew, J (1995) Differential diagnosis of polyneuritis equi.  ''In Practice'', Jan, 26-29.</ref>  EPM is one of the most frequently diagnosed neurological conditions of the Western Hemisphere (Furr) and the principal differential for multifocal, asymmetric progressive central nervous system (CNS) disease.<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''', third edition, SUDZ Publishing, 245-250.</ref>  As it can resemble any neurological disorder, EPM must be considered in any horse with neurological signs if it resides in the Americas or if it has been imported from that area<ref name="EPM8">Gray, L.C, Magdesian, K.G, Sturges, B.K, Madigan, J.E (2001) Suspected protozoal myeloencephalitis in a two-month-old colt.  ''Vet Record'', 149:269-273.</ref><ref name="EPM9">DEFRA, The Animal Health Trust, The British Equine Veterinary Association (2009) Surveillance: Equine disease surveillance, April to June 2009, ''The Vet Record'', Oct 24:489-492.</ref>  The disease is not contagious.<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''', third edition, SUDZ Publishing, 245-250.</ref>   

A progressive, infectious,<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''' (Third edition), ''SUDZ Publishing'', 245-250.</ref>neurological disease of horses, endemic in the USA<ref name="EPM8">Gray, L.C, Magdesian, K.G, Sturges, B.K, Madigan, J.E (2001) Suspected protozoal myeloencephalitis in a two-month-old colt.  ''Vet Record'', 149:269-273.</ref> and only encountered elsewhere in imported equids.<ref name="EPM3">Vatistas, N, Mayhew, J (1995) Differential diagnosis of polyneuritis equi.  ''In Practice'', Jan, 26-29.</ref>  EPM is one of the most frequently diagnosed neurological conditions of the Western Hemisphere<ref name="Furr">Furr, M (2010) ''Equine protozoal myeloencephalitis'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref> and the principal differential for multifocal, asymmetric progressive central nervous system (CNS) disease.<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''' (Third edition), ''SUDZ Publishing'', 245-250.</ref>  As it can resemble any neurological disorder, EPM must be considered in any horse with neurological signs if it resides in the Americas or if it has been imported from that area<ref name="EPM8">Gray, L.C, Magdesian, K.G, Sturges, B.K, Madigan, J.E (2001) Suspected protozoal myeloencephalitis in a two-month-old colt.  ''Vet Record'', 149:269-273.</ref><ref name="EPM9">DEFRA, The Animal Health Trust, The British Equine Veterinary Association (2009) Surveillance: Equine disease surveillance, April to June 2009, ''The Vet Record'', Oct 24:489-492.</ref>  The disease is not contagious.<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''', (Third edition), ''SUDZ Publishing'', 245-250.</ref>   

====Aetiology====

====Aetiology====

EPM results from infection of the CNS by the apicomplexan parasite ''Sarcocystis neurona'' or, less frequently, its close relative ''Neospora hughesi''.<ref>Dubey, J.P, Lindsay, D.S, Saville, W.J, Reed, S.M, Granstrom, D.E, Speer, C.A (2001)A review of ''Sarcocystis neurona'' and equine protozoal myeloencephalitis (EPM). ''Vet Parasitol'', 95:89-131. In: Pusterla, N, Wilson, W.D, Conrad, P.A, Barr, B.C, Ferraro, G.L, Daft, B.M, Leutenegger, C.M (2006) Cytokine gene signatures in neural tissue of horses with equine protozoal myeloencephalitis or equine herpes type 1 myeloencephalopathy.  ''The Vet Record'', Sep 9:''Papers & Articles''.</ref><ref>Wobeser, B.K, Godson, D.L, Rejmanek, D, Dowling, P (2009) Equine protozoal myeloencephalitis caused by ''Neospora hughesi'' in an adult horse in Saskatchewan.  ''Can Vet J'', 50(8):851-3.</ref>  These protozoans develop within neurons<ref name="Furr">Furr, M (2010) ''Equine protozoal myeloencephalitis'' in:</ref>  causing immediate or inflammatory-mediated neuronal damage.  The organisms migrate randomly through the brain and spinal cord causing asymmetrical lesions of grey and white matter and thus multifocal lower and upper motor neuron deficits.<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''', third edition, SUDZ Publishing, 245-250.</ref>

EPM results from infection of the CNS by the apicomplexan parasite ''Sarcocystis neurona'' or, less frequently, its close relative ''Neospora hughesi''.<ref>Dubey, J.P, Lindsay, D.S, Saville, W.J, Reed, S.M, Granstrom, D.E, Speer, C.A (2001)A review of ''Sarcocystis neurona'' and equine protozoal myeloencephalitis (EPM). ''Vet Parasitol'', 95:89-131. In: Pusterla, N, Wilson, W.D, Conrad, P.A, Barr, B.C, Ferraro, G.L, Daft, B.M, Leutenegger, C.M (2006) Cytokine gene signatures in neural tissue of horses with equine protozoal myeloencephalitis or equine herpes type 1 myeloencephalopathy.  ''The Vet Record'', Sep 9:''Papers & Articles''.</ref><ref>Wobeser, B.K, Godson, D.L, Rejmanek, D, Dowling, P (2009) Equine protozoal myeloencephalitis caused by ''Neospora hughesi'' in an adult horse in Saskatchewan.  ''Can Vet J'', 50(8):851-3.</ref>  These protozoans develop within neurons<ref name="Furr">Furr, M (2010) ''Equine protozoal myeloencephalitis'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref>  causing immediate or inflammatory-mediated neuronal damage.  The organisms migrate randomly through the brain and spinal cord causing asymmetrical lesions of grey and white matter and thus multifocal lower and upper motor neuron deficits.<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''' (Third edition), ''SUDZ Publishing'', 245-250.</ref>

====Signalment====

====Signalment====

Mostly Standardbreds and Thoroughbreds aged 1-6years.<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''', third edition, SUDZ Publishing, 245-250.</ref>  Foal infection may be possible.<ref name="EPM8">Gray, L.C, Magdesian, K.G, Sturges, B.K, Madigan, J.E (2001) Suspected protozoal myeloencephalitis in a two-month-old colt.  ''Vet Record'', 149:269-273.</ref>   

Mostly Standardbreds and Thoroughbreds aged 1-6years.<ref name="Pasq">Pasquini, C, Pasquini, S, Woods, P (2005) '''Guide to Equine Clinics Volume 1: Equine Medicine''' (Third edition), ''SUDZ Publishing'', 245-250.</ref>  Foal infection may be possible.<ref name="EPM8">Gray, L.C, Magdesian, K.G, Sturges, B.K, Madigan, J.E (2001) Suspected protozoal myeloencephalitis in a two-month-old colt.  ''Vet Record'', 149:269-273.</ref>