Exam 4 - envenomations Flashcards
Most snake bites are from what group of snakes in animals?
Pit Vipers (rattlesnakes, water moccasin, copperheads)
primary copperheads
Is coral snake toxin primarily neurotoxic or causing local tissue pain and damage?
neurotoxic “curare-like” syndrome
Why should a dog potentially bitten by a coral snake be observed over an extended period of time?
Delayed onset of clinical signs (~12 hours
How would you treat a cat presenting with a known coral snake bite and who is beginning to be symptomatic?
compression bandage around/over the bite site
ventilatory support if respiratory collapse, dysphagia and aspiration pneumonia
Abx only if 2o infection
adequate supportive care!
main complications of coral snake bite
aspiration pneumonia
treatment for rattlesnake bite
IV crystalloid fluid
diphenhydramine
antivenin (stops progression, enhances recovery - NOT prevention)
What are the 3 general types of rattlesnake venom? What do they cause in affected animals?
1) Classic Diamondback Rattlesnake Venom – tissue destruction, coagulopathy, hypotension
2) Mojave A Rattlesnake Venom – severe neurotoxicosis (NO tissue destruction or coagulopathy)
3) Intergrade found in multiple species – both neurotoxins and classic venom components
Why will pit viper antivenins or vaccines potentially only be active against a sub-set of envenomations?
- complex mixture of enzymatic and nonenzymatic proteins (min of 10 enzymes in a specific venom)
- response to venom components varies widely depending on the snake, volume of venom injected and species of recipients
How would you tell if a rattlesnake bite occurred and the potential seriousness in a dog who may have been bitten?
Check for puncture wounds (dogs esp on head, front legs)
SWELLING
petechiation and ecchymosis
onset of signs may be delayed hours
marked hypotension often develops early
what diagnostics can be done to see if a dog was bitten by a rattlesnake?
baseline blood counts
serum chems
CK would be high
coag parameters
urinalysis for hematuria/rhabdomyolysis
non-EDTA blood smear - Ecchinocytosis (due to phospholipases in venom)
What does Gila Monster venom cause? How do you treat a known envenomation?
extreme pain at bite site & hypotension
supportive care
IV fluids
pain meds (narcotics or fentanyl - NSAIDs not strong enough)
irrigate wound with lidocaine and probe for teeth
What species is especially sensitive to widow bites? How would you treat a known bite in this species?
cats - paralysis, pain, Cheyne-stokes resp pattern “latrodectism syndrome”
opiods
diazepam & methocarbamol
antivenin Lycovac
widow spider toxin
alpha-latroxin (neuroactive proteins)
difference between a widow spider, recluse and funnel web spider
recluse & funnel web spiders males more toxic than females
widow spiders females more toxic than males
Recluse spider toxin
necrotizing enzymes (e.g. sphingomyelinase D that increases neutrophil migration)
inactivates serum hemolytic complement
What is the primary lesion seen after a recluse spider bite? How would you treat it?
“bulls eye lesion”
wound care
debridement w burrow solution or H2O2 + bandaging
diphenhydramine
Abx if infection
analgesics for pain
dapson for inhibition of neutrophil migration
Hobo spiders toxin & their significance
tegenarism
wound may take 3 years to heal if in fatty tissue
funnel web spiders toxin and significance to dogs/cats
neurotoxin “rubustoxin”
dogs/cats relatively resistant
Are tarantulas dangerous?
Species in the US are not capable of delivering serious envenomation
those in South America, Australia and Africa are capable of delivering a toxic venom (e.g. Selenocosmia & Phlogiellus)
tarantula toxins
neurotoxin
necrotoxin
hemolytic toxin
MOA of scorption toxins
What are the consequences of a scorpion sting?
Is it a serious concern in dogs or cats?
𝛼-scorpion toxin & 𝛽-scorpion neurotoxins (block voltage sensitive Na+ and K+ channels)
sharp pain, edema, pruritis, LN enlargement, allergic rxn
NO evidence in dogs/cats it is a serious concern - 100% fatal in ferrets
What does tick toxin cause? How do you treat it?
tick paralysis (one or few ticks) - LMN paralysis & paresis
remove ticks
supportive care
topical insecticides
What do you primarily need to worry about regarding bee and/or wasp stings?
anaphylaxis due to protein components (phospholipases & hyaluronidases)
bees - one sting
wasp - multiple stings
bee venom can cause bronchiolar muscles to contract in cats
Myriapoda (centipedes & millipedes) toxins & effect
serotonin, cytolysin, hemolysin, vesicating agent
irritants (esp secretions from millipedes repugnatorial glands)
red fire ant toxins and effect
alkaloids = no anaphylaxis
pain, erythematous plaques
