Large Animal Multifocal Spinal Cord Disease Flashcards
what is a differential diagnosis for any manifestation of neurological disease in the horse?
equine protozoal myeloencephalitis
what is a classic equine protozoal myeloencephalitis case?
asymmetric spinal cord disease
individual cranial nerves may be affected
what are the etiologic agents of equine protozoal myeloencephalitis?
Sarcocystis neurona
Neospora hughesi
what stages of the agents of equine protozoal myeloencephalitis have been identified in the horse?
asexual stages
aberrant intermediate host
what is the gross pathology of equine protozoal myeloencephalitis?
focal discoloration
hemorrhage
+/- malacia of CNS
often unilateral lesions
what is the best test for equine protozoal myeloencephalitis?
CSF titer ratio
what commercial testing is available for equine protozoal myeloencephalitis?
indirect fluorescent antibody test
ELISAs
how do horses with equine protozoal myeloencephalitis usually respond to treatment?
often improve by only 1-2 grades
who does Parelaphostrongylus tenuis impact?
US camelids most commonly
also goats and sheep
what neurological signs are associated with Parelaphostrongylus tenuis?
general proprioceptive
upper motor neuron
lower motor neuron
may involve brain (less common)
what is the definitive host of Parelaphostrongylus tenuis?
white-tailed deer
how long does it take Parelaphostrongylus tenuis L3 to reach meninges of aberrant hosts after being ingested?
1 month
how can you diagnose Parelaphostrongylus tenuis?
lumbosacral CSF tap
eosinophilic pleocytosis of CSG
what are the aberrant hosts of Parelaphostrongylus tenuis?
camelids
sheep
goats
moose
what is seen with the vascular endothelium with equine herpes virus-1 myeloencephalopathy?
vasculitis
thrombo-ischemia
what can distinguish equine herpes virus-1 myeloencephalopathy from other neural diseases?
bladder dysfunction
what does it mean that equine herpes virus-1 myeloencephalopathy is endotheliotropic?
localizes in small vessels of CNS
how does equine herpes virus-1 myeloencephalopathy spread?
aerosolization of respiratory secretions
what is equine degenerative myeloencephalopathy?
diffuse non-compressive spinal cord disease
degeneration of neurons in white matter of spinal cord
what is the main clinical sign of equine degenerative myeloencephalopathy?
acute or slowly progressive symmetric proprioceptive ataxia
what can cause diffuse corticospinal disease?
equine degenerative myeloencephalopathy
what viruses can cause multifocal spinal disease?
equine herpes virus I
west nile virus
eastern equine encephalitis
what does a classic equine protozoal myeloencephalitis look like?
asymmetric:
general proprioceptive, upper motor neuron, and lower motor neuron
caudal to L2
often ventral horn
no fever
individual cranial nerves may be affected
what is the definitive host of Sarcocystis neurona and Neospora hughesi?
opossum
how often are protozoa seen with equine protozoal myeloencephalitis?
rarely: 25%
what is the cycle of Paralaphostrongylus tenuis infecting an aberrant host?
L3 ingested to abomasum
go to spinal cord
subdural space of cranium
alveoli of lungs: eggs laid
when do neurologic signs develop with equine herpes virus I myeloencephalopathy?
6-10 days after infection
what path does equine herpes virus I take in infection?
respiratory epithelial cells
regional lymph nodes to peripheral blood leukocytes
what is the pathophysiological mechanism of equine degenerative myeloencephalopathy?
neurodegenerative
nutritional
hereditary
what do elisas for equine protozoal myeloencephalitis test?
IgG response to unique surface antigens
