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17 Cards in this Set
- Front
- Back
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sarcocystis hosts |
asexual stage in intermediate host (prey)- might cause mild/subclinical sexual stage in definitive host (preditor)- wont cause disease |
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sarcocystis life cyc
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sporocyst in feces ingested by herbivore/prey- from GI to blood (schizonts in endothelial cells- merozoite free in blood) to form cysts in muscle- infects definitive host when they eat the muscle- encyst in wall- sexual reproduction- release sporocysts
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typical intermediate host experience |
show minimal disease (often incidental finding) no inflammatory reaction, no pain
EXCEPT in horses and sea mammals |
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species in ruminants |
S cruzi- cow S capracanis- goat S tenella- sheep |
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pathology in ruminants |
disease associated with schizogony in endothelial cells--> cell damage- hemmorrhage and infl severe signs when they rupture |
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symptoms in rum |
acute phase: fever, anorexia, poor growth, anemia, emaciation, abortion, death, edema, hemorrhage
chronic phase: subclinical, nonsupperative myositis |
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rum diagnosis and treatment |
not needed most animals are seropositive with no signs histopath is only definitive way treat with coccidiostat |
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The aberrant host symptoms |
Goes to the brain/spinal cord to cause neurologic signs
slow or acute onset
variable depending on location, often multifocal
lameness, atrophy (LMN) spinal ataxia (UMN) dysphagia, facial paralysis, vestibular (CN) cerebellar/forebrain uncommon |
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aberrant host disease |
equine protozoal myeloencephalitis (EPM)
causes inflammation of the sipinal cord and brain |
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causes of EPM |
Requires the parasite to be in the CNS sarcocystis neurona neospora hughesi (much less common)
passed in opossum feces- most horses have been exposed but clear infection before it gets to brain |
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sarcocystis neurona |
unusual from opossum (definitive) intermediate host is not an herbivore |
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EPM diagnosis |
many many are seropositive but not infected variable clinical signs never know definitively without necropsy
3 principles 1. clinical signs 2. exclusion of other disease 3. proof of exposure (serology) |
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lab diagnostics |
test for antibodies MANY false pos CSF tap best BUT there can be blood contamination or diffusion from blood--> only a high CSF conc will be truly suggestive |
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diagnostic tests |
Western blot Indirect fluorescent antibody test (IFAT) surface antigen ELISA
blood or CSF fine |
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treatment |
low rate of improvement, even lower that return to normal--> due to physical damage to the cells- can't undo this |
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prognosis |
60% improve 15% return to normal 10-25% relapse (ie unsuccessful treatment)
acute is due to infl not damage- better prognosis chronic is worse, intracranial signs worse young, old, and immune compromised horses more susceptible
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disease in marine mammals |
Marine mammal protozoal encephalitis multiple parasites increases mortality often in cerebellum |
