equine dysautonomia Flashcards
Equine dysautonomia is described in the US?
yes, one case in a mule in the US
Supportive factors for involvement of Clostridium Botulinum in ED
- reported sucessful historic botulinium vaccine trial
- greater prevalence of intestinal C botulinium and/or tocin in patients with ED vs control
- risk factor supportive of involvemebr of a soil-borne agent
- inverse association between disease risk and systemic concentration of antibodies against C Bot bacteria and toxin
- higher mucosal IgA against BoNT/C and D in patient with acute ED vs control
refutative factor for involvement of Clostridium Botulinium in equine dysautonomia
- disease phenotipic difference between ED and neuroparalytic botulism
- greather prevalence of other (non C-bitulinium) clostridial specied in intestinal tract of patient with ed vs controls
- neuropthology apparent incontsistent with action of C bootulinium neurotoxin
- lack of evidence of temporal and geographic clustering of ED and neuroparalytic botulism cases
Supportive factors for involvement of mycotoxin in ED
association with grazing, seasonality, geographic and temporal clustering of cases
factor associated with increased occurence of ED : horse level
- age (2-7 y)
- low serum antibodies to C Botulinium and BoNT/C
- good body condition
- contact with prevoious patient with ED
factor associated with increased risk of ED:
premises level
previous ED occurence on premises (occ)
high soil nitrogen content (occ)
pasture/soil disturbance (occ)
high number of horses (occ)
presence of younger animal (occ/rec)
stud farms/ livery and riding establishment (rec)
loam and sandy soil (rec)
rearing of domestic birds (rec)
high herbage iron, lead, arsenic, chromium (ass)
abundance of ranunculus spp (buttercups) (ass)
high soil titanium (occ)
low soil zinc and chromium (occ)
chalk soil (decrase rec)
factor associated with increased risk of ED
management level
grazing (occ)
recent movement (especially within preceding 2 weeks) (occ)
change in feed type/quantity within preceding 2 weeks (occ)
ultimate and penultimate use of an ivermectine-based antihelminthic (occ)
mechanical removing of feces from pasture (rec)
manual removing of feces from pasture (decrease rec)
grass cutting (decrease rec)
cograzing with ruminant (dec rec)
feeding of supplementary hay/haylage (dec occ)
factor associated with increased risk of ED
climate level
recent (within 10-14d) cool, dry weather and irregular ground frosts (occ)
increase sun hours and frost days (occ)
higher averge max temperature ( dec occ)
clinical signs present in acute/subacute and chronic ED
dull deleanor, reduced appetite, bilateral ptosis (almost invariably present), rhinnitis sicca, dysphagia, sweating, muscle tremors (triceps, flanc, quadriceps), elevated temperature
clinical signs only present in acute ED
marked tachycardia (60-120 bpm), hypersalivation (maj acute, intermittent), abdominal pain, , absence of intestinal sound, intestinal distention
prognostic indicator in chronic ED
degree of dysphagia
clinical signs only present in chronic ED
base-narrow stance, tucked-up abdominal silhouette, stertor resulting from rhinnitis sicca, paraphimosis, esophageal choke abd aspiration
blood test abnomalities in ED
increase hematocrit, elevated serum urea concentration, elevated serum acute phase protein concentration, elevated urine specific gravity, protein and creatinine concentration, fecal C perfringens detection (ELISA), elevated peritoneal fluid specific gravity ans prot cocentration
diagnostic test for ANS/ ENS dysfonction in ED
- temporary reversal of ptosis following topical application of 0.5% phenylephrine
- barium swallow study (retrograde flow)
- esophagoscopy (retrograde flow)
-nasogastric intubation (voluminous foul smeling gastric fluid reflux) - abdominal US (distended small intestine loops)
- transrectal palapation (generalised intestinal ileus, dessication of fibrous ingesta)
histopathological examination of ileal biopsy in ED
1/ HE: neuronal loss and chromatolysis within myenteric ans submucous plexuses
formalin fixed: 100% sensitive and specific
cryostat section: suboptimal (73%) specificity (processing artifact)
2/ synaptophysin immunostaining: combined assesseme,nt of neuronal density and intensity of synapto, 100% sensitivity and specificity