Changes

====Pathology====

====Pathology====

Widespread lesions of the CNS are typically observed in horses.<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>  

Widespread lesions of the CNS are typically observed in horses.<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>  

=====Gross exam=====  

=====Gross exam=====  

=====Histopathology=====

=====Histopathology=====

Microscopically, both grey and white matter may be affected with focal to diffuse areas of nonsuppurative inflammation, necrosis and neuronal destruction.  Perivascular infiltrates comprise lymphocytes, macrophages, plasma cells, giant cells, eosinophils and gitter cells.<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>  

Microscopically, both grey and white matter may be affected with focal to diffuse areas of nonsuppurative inflammation, necrosis and neuronal destruction.  Perivascular infiltrates comprise lymphocytes, macrophages, plasma cells, giant cells, eosinophils and gitter cells.<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> In around 25% of cases, schizonts or merozoites may be found in the neuronal cytoplasm (Merck).  Less frequently, protozoa parasitize intravascular and tissue neutrophils and eosinophils, capillary endothelial cells and myelinated axons<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> (Merck).  Free merozoites may be seen in necrotic regions.  If organisms are absent, the diagnosis relies on recognition of the inflammatory changes described above. (Merck)

  In around 25% of cases, schizonts or merozoites may be found in the neuronal cytoplasm (Merck).  Less frequently, protozoa parasitize intravascular and tissue neutrophils and eosinophils, capillary endothelial cells and myelinated axons<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> (Merck).  Free merozoites may be seen in necrotic regions.  If organisms are absent, the diagnosis relies on recognition of the inflammatory changes described above. (Merck)

 

====Prognosis====

====Prognosis====