EQUINE NAVLE REVIEW QUESTIONS
AND ANSWERS.
Encephalitis Viruses: EEE, WEE, VEE -
\mosquito vector, bird reservoir
zoonotic
viral encephalitis cause . . . -
\young horses 1-3yr
signs 3-5 days PI
fever, depression, behavior change
diffuse cerebral +/- spinal cord signs
Viral Encephalitis DX -
\CSF pleocytosis (EEE = neutrophilic)
IgM Capture ELISA
Viral Encephalitis TX -
\supportive
mortality EEE (75+) > VEE > WEE
recover - retain neuro deficits
Pathology of Viral Encephalitis -
\grey matter: cerebrum, thalamus, hypo
acute = neutrophils (EEE!)
sub-acute, chronic = lymphocytes
Control of Viral Encephalitis -
\vaccination, mosquito control
West Nile Virus -
\humans, birds, horses, reptiles, camelids
September/October
via mosquito bite
crosses BBB
WNV Signs -
\muscle fasciculations
cranial nerve defecits
progressive sudden ataxia
full recovery possibly in 1-6mo
grey matter
,WNV DX -
\IgM Capture ELISA
WNV Prevention -
\vaccination, mosquito control
Rabies -
\saliva contamination of wound
incubation = 2-9wk in horse (hours-months)
salivary glands shed b/f signs
Rabies Signs -
\can look like anything: death in 1-8d of signs
fever common
hyperesthesia, ataxia, colic, dysphagia
Rabies DX -
\IFA on chilled brain (NOT frozen, formalin)
Negri bodies = intracyto. eos. inclusions
Equine Herpesvirus Myeloencephalopathy -
\EHV-1 = neuro, abortion, respiratory
respiratory route
fomites
latency in trigeminal ganglion
shed up to 3wk
EHV-1 Risk Factors -
\vaccination w/n 12 mo
females, older, spring/winter
fever
Equine Herpesvirus Myeloencephalopathy Signs -
\6-10d PI
FEVER >> ataxia, parasis >> bladder atony, urinary incontinence
improve in 5-7d (standing = recovery)
Equine Herpesvirus Myeloencephalopathy DX -
\CSF = xanthochromia, + prot
**PCR on buffy coat or nasal swab
Equine Herpes Myeloencephalopathy TX and Prevention -
\supportive, NSAIDs
neuro vaccine unproven
Equine Protozoal Myeloencephalitis -
, \Sarcocystis neurona
multifocal ASYMMETRIC disease
can do anything: asymmetry, atrophy, ataxia
grey matter
DX: snSAG ELISA, IFAT
EPM Life Cycle -
\opossum (DH)
armadillo, skunk, cat, bird (IH)
horses dead end host
EPM TX -
\frustrating = 30-60+ days
Ponazuril (Marquis)
Sulfonamide + Pyrimethamine
no vaccine
Tetanus (Clostridium Tetani) -
\spore forming anaerobe
wounds: incubate 2-4wk
3 exotoxins - block inhibitory NTs
Tetanus Signs -
\stiff gait, trismus, **prolapse of TE**, dyspaghia
RIGID paralysis
"sawhorse" stance
if alive after 7 days - often complete recovery
Tetanus TX -
\penicillin = kill organism
antitoxin = neutralize toxin
Tetanus Prevention -
\toxoid vaccination
antitoxin in special situations only
Botulism (Clostridium botulinum) -
\ingest toxin (forage)
toxicoinfectious (formed in GIT)
wound
signs in 8-10hr PI
Botulism Signs -
\flaccid paralysis, poor tongue tone
CNS and sensory nerves spared
respiratory arrest
AND ANSWERS.
Encephalitis Viruses: EEE, WEE, VEE -
\mosquito vector, bird reservoir
zoonotic
viral encephalitis cause . . . -
\young horses 1-3yr
signs 3-5 days PI
fever, depression, behavior change
diffuse cerebral +/- spinal cord signs
Viral Encephalitis DX -
\CSF pleocytosis (EEE = neutrophilic)
IgM Capture ELISA
Viral Encephalitis TX -
\supportive
mortality EEE (75+) > VEE > WEE
recover - retain neuro deficits
Pathology of Viral Encephalitis -
\grey matter: cerebrum, thalamus, hypo
acute = neutrophils (EEE!)
sub-acute, chronic = lymphocytes
Control of Viral Encephalitis -
\vaccination, mosquito control
West Nile Virus -
\humans, birds, horses, reptiles, camelids
September/October
via mosquito bite
crosses BBB
WNV Signs -
\muscle fasciculations
cranial nerve defecits
progressive sudden ataxia
full recovery possibly in 1-6mo
grey matter
,WNV DX -
\IgM Capture ELISA
WNV Prevention -
\vaccination, mosquito control
Rabies -
\saliva contamination of wound
incubation = 2-9wk in horse (hours-months)
salivary glands shed b/f signs
Rabies Signs -
\can look like anything: death in 1-8d of signs
fever common
hyperesthesia, ataxia, colic, dysphagia
Rabies DX -
\IFA on chilled brain (NOT frozen, formalin)
Negri bodies = intracyto. eos. inclusions
Equine Herpesvirus Myeloencephalopathy -
\EHV-1 = neuro, abortion, respiratory
respiratory route
fomites
latency in trigeminal ganglion
shed up to 3wk
EHV-1 Risk Factors -
\vaccination w/n 12 mo
females, older, spring/winter
fever
Equine Herpesvirus Myeloencephalopathy Signs -
\6-10d PI
FEVER >> ataxia, parasis >> bladder atony, urinary incontinence
improve in 5-7d (standing = recovery)
Equine Herpesvirus Myeloencephalopathy DX -
\CSF = xanthochromia, + prot
**PCR on buffy coat or nasal swab
Equine Herpes Myeloencephalopathy TX and Prevention -
\supportive, NSAIDs
neuro vaccine unproven
Equine Protozoal Myeloencephalitis -
, \Sarcocystis neurona
multifocal ASYMMETRIC disease
can do anything: asymmetry, atrophy, ataxia
grey matter
DX: snSAG ELISA, IFAT
EPM Life Cycle -
\opossum (DH)
armadillo, skunk, cat, bird (IH)
horses dead end host
EPM TX -
\frustrating = 30-60+ days
Ponazuril (Marquis)
Sulfonamide + Pyrimethamine
no vaccine
Tetanus (Clostridium Tetani) -
\spore forming anaerobe
wounds: incubate 2-4wk
3 exotoxins - block inhibitory NTs
Tetanus Signs -
\stiff gait, trismus, **prolapse of TE**, dyspaghia
RIGID paralysis
"sawhorse" stance
if alive after 7 days - often complete recovery
Tetanus TX -
\penicillin = kill organism
antitoxin = neutralize toxin
Tetanus Prevention -
\toxoid vaccination
antitoxin in special situations only
Botulism (Clostridium botulinum) -
\ingest toxin (forage)
toxicoinfectious (formed in GIT)
wound
signs in 8-10hr PI
Botulism Signs -
\flaccid paralysis, poor tongue tone
CNS and sensory nerves spared
respiratory arrest
