Exam 4: Envenomations

Question 1

Most snake bites are from what group of snakes in animals?

Answer 1

Crotalidae (pit vipers)

Question 2

Is coral snake toxin primarily neurotoxic or causing of local tissue pain and damage?

Answer 2

Primarily neurotoxic with little local tissue reaction of pain at the bite site

Question 3

Why should a dog potentially bitten by a coral snake be observed over an extended period of time?

Answer 3

Venom uptake can be delayed by a number of hours
Onset of neurological signs is often delayed up to 12 hours or more

Question 4

How would you treat a cat presenting with a known coral snake bite and who is beginning to be symptomatic?

Answer 4

Use of compression bandage round and over the bite site
Be prepared to respond to respiratory collapse, dysphagia, and aspiration pneumonia
Ventilatory support +/- broad spectrum abx

Question 5

What are the 3 general types of rattlesnake venom? What do they cause in afflicted animals?

Answer 5

Classic diamondback = marked tissue destruction, coagulopathy, hypotension
Mojave A = virtually no tissue destruction or coagulation defects but it induces severe neurotoxicosis
Intergrade = contains both neurotoxins and classic venom components

Question 6

Why will pit viper antivenins or vaccines potentially only be active against a sub-set of envenomations?

Answer 6

The vaccine elicits an immune response to the major protein fractions of the Western diamondback rattlesnake - does not cross react with other venoms

Question 7

How would you tell if a rattlesnake bite occurred and the potential seriousness in a dog who may have been bitten?

Answer 7

Marked regional swelling (ecchymosis, petechiation)
Marked hypotension often develops early
Swelling is progressive for up to 36 hours after envenomation
Tachycardia, shallow respirations, lethargy, nausea, obtundation, muscle fasciculations, increased salivation, enlarged LNs
Dogs usually bitten on head or front legs

Question 8

What diagnostic tests can be done for rattlesnake envenomations?

Answer 8

Early high levels of creatine phosphokinase
Monitor coagulation measures (aPTT, PT, fibrinogen)
Urinalysis (hematuria, rhadbomyolysis)
Non-EDTA blood smear = echinocytosis

Question 9

What does Gila Monster venom cause?

Answer 9

Extreme pain at bite site
Bleeding, edema, hypotension and tachycardia

Question 10

How do you treat a known Gila Monster envenomation?

Answer 10

Remove lizard
Hospitalize and monitor
IV fluids (hypotension), narcotics (pain), abx (infection)

Question 11

What species is especially sensitive to widow bites?

Answer 11

Cats

Question 12

How would you treat a known widow bite in cats?

Answer 12

Opioids (pain)
Diazepam, methocarbamol (muscle rigidity)

Question 13

What is the primary lesion seen after a recluse spider bite?

Answer 13

“Bullseye lesion” - redness, swelling, tenderness

Question 14

How would you treat a recluse spider bite?

Answer 14

Necrotic lesions = debridement with Burrows solution or H2O2, diphenhydramine, abx
Pain = analgesics
Dapsone

Question 15

Are tarantulas dangerous?

Answer 15

No
South America, Africa, Australia = neurotoxic

Question 16

What are the consequences of a scorpion sting?

Answer 16

Instant, sharp pain
Localized edema, pruritus
Ln enlargement +/- allergic reaction (facial swelling, vomiting)
Numbness of face, myalgia, tachycardia, bradycardia, respiratory depression, seizures

Question 17

Are scorpion stings a serious concern in dogs and cats?

Answer 17

Lack of evidence that scorpion envenomation in dogs and cats is a serious concern

Question 18

What does tick toxin cause?

Answer 18

Paralysis
Ascending ataxia that progresses to paresis and flaccid paralysis

Question 19

How do you treat tick intoxication?

Answer 19

Remove the ticks and provide supportive care, especially respiratory support, until recovery occurs
Use of topical insecticides

Question 20

What do you primarily need to worry about regarding bee and/or wasp stings?

Answer 20

A single sting rarely causes more than a transient, painful prick in animals
Local reactions = swelling, edema, erythematous plaques
Multiple stings = prostration, convulsions, CNS depression, shock, hyperthermia, bloody diarrhea/vomiting, leukocytosis, hemolysis, renal/hepatic toxicity