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Equine Protozoal Myeloencephalitis (view source)
Revision as of 18:52, 17 July 2010
, 18:52, 17 July 2010no edit summary
|Cervical vertebral malformation (CVM, cervical compressive myelopathy, cervical vertebral instability, cervical spondylomyelopathy, Wobbler's syndrome)
|Cervical vertebral malformation (CVM, cervical compressive myelopathy, cervical vertebral instability, cervical spondylomyelopathy, Wobbler's syndrome)
|Symmetrical gait deficits, worse in pelvic limbs<ref>Mayhew, I.G, deLahunta, A, Whitlock, R.H, Krook, L, Tasker, J.B (1978) Spinal cord disease in the horse, ''Cornell Vet'', 68(Suppl 8):110-120. In: Hahn, C.N (2010) ''Cervical Vertebral Malformation'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref> with spasticity and dysmetria, good retention of strength, no muscle wasting<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> '''NB:can be concurrent with EPM'''.<ref name="Hahn">Hahn, C.N (2010) ''Cervical Vertebral Malformation'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref>
|Symmetrical gait deficits, worse in pelvic limbs<ref>Mayhew, I.G, deLahunta, A, Whitlock, R.H, Krook, L, Tasker, J.B (1978) Spinal cord disease in the horse, ''Cornell Vet'', 68(Suppl 8):110-120. In: Hahn, C.N (2010) ''Cervical Vertebral Malformation'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref> with spasticity and dysmetria, good retention of strength, no muscle wasting<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> '''NB:can be concurrent with EPM'''.<ref name="Hahn">Hahn, C.N (2010) ''Cervical Vertebral Malformation'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref>
|Standing plain lateral radiography of C1 to T1<ref name="Hahn">Hahn, C.N (2010) ''Cervical Vertebral Malformation'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref>, myelography. <ref name="Seino">Seino, K.K (2010) ''Spinal Ataxia'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 3.</ref>
|Plain lateral radiography of C1 to T1<ref name="Hahn">Hahn, C.N (2010) ''Cervical Vertebral Malformation'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref>, myelography. <ref name="Seino">Seino, K.K (2010) ''Spinal Ataxia'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 3.</ref>
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|WNV encephalitis
|WNV encephalitis
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|[[Equine Togaviral Encephalitis|EEE]]
|[[Equine Togaviral Encephalitis|EEE]]
|Systemically ill, pyrexia, abnormal motor function<ref name="Long">Long, M.T (2010) ''Flavivirus Encephalitis'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref, rapidly progressive (seino, p134)
|Systemically ill, pyrexia, abnormal motor function<ref name="Long">Long, M.T (2010) ''Flavivirus Encephalitis'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref, rapidly progressive.<ref name="Seino">Seino, K.K (2010) ''Spinal Ataxia'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 3.</ref>
|Leukogram, CSF analysis, ELISA, titres, viral isolation
|Leukogram, CSF analysis, ELISA, titres, viral isolation
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|Equine herpesvirus-1 myeloencephalopathy
|Equine herpesvirus-1 myeloencephalopathy
|Sudden onset and early stabilization of neuro signs, multiple horses affected, recent fever, abortion<ref>Wilson, W.D, Pusterla, N (2010) ''Equine Herpesvirus-1 Myeloencephalopathy'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref>dysuria not often seen in EPM.
|Sudden onset and early stabilization of neuro signs, multiple horses affected, recent fever, abortion<ref>Wilson, W.D, Pusterla, N (2010) ''Equine Herpesvirus-1 Myeloencephalopathy'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12.</ref>dysuria not often seen in EPM.
|CSF abnormal, PCR<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>, titres, virus isolation.<ref name="Seino">Seino, K.K (2010) ''Spinal Ataxia'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 3.</ref>
|CSF analysis, PCR<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>, titres, virus isolation.<ref name="Seino">Seino, K.K (2010) ''Spinal Ataxia'' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 3.</ref>
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|Rabies
|Rabies
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====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>
=====Gross exam=====
Lesions may be up to several centimetres across.<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> They range from mild discolouration to multifocal areas of haemorrhage and/or malacia (Merck) of the brain, spinal cord and less commonly, peripheral nerves.<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>
=====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>
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====