Unit 2 - Neuro 3 Flashcards
What causes Eastern and Western Equine Encephalomyelitis?
Alphavirusus - togaviridae
What sylvantic hosts do EEE and WEE survive in during the winter months?
birds, small mammals, and reptiles
What is the main vector for WEE and EEE?
mosquitos
What else can transmit WEE?
ticks, assassin bug, and cliff swallow bug
How else can EEE be transmitted?
via nasal secretions
What is the peak season for transmission of EEE and WEE?
June to November
What is the mortality rate for WEE?
25-50%
What is the mortality rate for EEE?
50-70%
What are the initial clinical signs of WEE and EEE?
Mild fever, stiffness
What are the clinical signs 1-3 weeks post infection of WEE and EEE?
Mild fever, obtundation
What clinical signs are associate with further progression of WEE and EEE infection?
Cerebrothalmic signs, compulsive walking, altered behavior, hyperesthesia, recumbency, death
What cranial nerves does obtundation affect?
CN 7, 8, 9, 10, and 12
How is EEE and WEE diagnosed?
Time of year + clinical signs, capture IgM ELISA, CSF, and post mortem
What is the gold standard antemortem test for EEE and WEE?
Capture IgM ELISA
How is EEE and WEE treated?
Non-specific supportive care (hydration, nutrition, ensuring urination and defecation), NSAIDs, and +/- steroids (controversial)
How is EEE and WEE prevented?
appropriate vaccination (2 vaccine series with 6 mo and 1 year boosters) and mosquito control
What is the etiologic agent of West Nile Viurs?
Flavivirus
What is the reservoir host for WNV?
birds and wild vertebrates
How does the WNV access the CNS?
It enters the CNS via hematogenous and transneural access via a disrupted BBB
What is the peak season for WNV transmission?
July to October
What are the clinical signs of WNV?
Weakness, ataxia, altered mentation, fever, muscle fasciculations, CN deficits, recumbency, paralysis of 1 or more limbs, and narcolepsy-like behavior
What is the antemortem gold standard diagnosis for WNV?
IgM capture ELISA
What will WNV look like at necropsy?
polioencephalomalacia
How is WNV treated?
Non-specific supportive care (hydration, nutrition, ensuring urination and defecation), NSAIDs, and +/- steroids (controversial)
How is WNV prevented?
appropriate vaccination (2 vaccine series with 4 mo and 1 year boosters) and mosquito control
What are the initial clinical signs of tetanus?
stiff neck, trismus, rigid facial expression, and prolapse of nictitans membrane (3rd eyelid)
What are the clinical signs 1-2 days post tetanus infection?
Generalized spasticity, sawhorse stance, elevated tail head, tonic muscle spasms, pharyngeal, laryngeal spasp, and dramatic fluctuations in HR
How is tetanus diagnosed?
history, clinical signs, can gram stain wound, can submit wound exudate for toxin assay
How is tetanus treated?
Clean and debride wound if present, treat infection, imuscle relaxation, neutralization of circulating toxin, ensure hydration, nutrition needs are met
What is the prognsis for tetanus?
75% mortality rate in horses
Poor prognosis if recumbent
Usually stabilize in 2-7 days and then slowly improve
How is tetanus prevented?
Initial 2 vaccines 3-6 weeks apart then yearly boosters. Re-booster before surgery, at the time of surgery
What are the clinical signs of Botulism?
Tongue weakness, dysphagia, lethargy, muscle weakness, weak facial muscles, stilted hypometric gait, difficulty standing, and mydriasis, decreased PLR
How is botulism diagnosed?
Clinical signs and you can test GI contents, feed, wound exudate etc. for toxin
How do you differentiate between Botulism and Nigropallidal encephalomalacia infection?
Horses with botulism can’t swallow, but horses with NE can
How is Botulism treated?
Early administration of anti-toxin - it has minimal efficacy in recumbent horses, clinical signs may progress for 12-24 hours post administration
Prophylactic antimicrobials in case of aspiration pneumonia
Fluid and nutritional therapy
What is the prognosis for botulism if not recumbent?
7-14 days for resolution of dysphagia and 1 month for resolution of full limb strength
What is the prognosis for botulism if recumbent?
poor
How is botulism prevented?
BoNT/B vaccine in endemic areas (3 part series administered 4 weeks apart and then once yearly)
