Lecture 4 Flashcards by Danika Boltz

What are the characteristics of pit vipers?

-largest group of venomous snakes in US
-copperhead bites are most common
-rattlesnake bites are more likely to be fatal

How well did you know this?

Not at all

Perfectly

What is the anatomy of pit vipers?

-triangular head
-vertical, elliptical pupils
-bilateral, heat-sensing pits
-retractable front fangs

How well did you know this?

Not at all

Perfectly

What are the characteristics of pit viper venom amounts?

-defensive strikes are less envenomating
-larger snakes produce larger volumes
-rattlesnakes can control venom delivery
-cats more resistant; larger volumes to have similar effects as in dogs

How well did you know this?

Not at all

Perfectly

What are the effects of pit viper venom?

-prey immobilization and partial digestion
-local tissue injury/inflammation/necrosis
-platelet aggregation/thrombocytopenia/hemolysis
-cardiovascular and respiratory compromise
-neurologic dysfunction

How well did you know this?

Not at all

Perfectly

What are the characteristics of pit viper bites?

-1 to 2 punctures seen
-commonly seen on head and neck
-swelling migrates ventrally
-upper airway obstruction uncommon despite swelling

How well did you know this?

Not at all

Perfectly

What are the clinical signs of pit viper bites?

-pain
-progressive edema
-mild hemorrhage
-petechiation/ecchymosis/necrosis

How well did you know this?

Not at all

Perfectly

What are the clinical signs of pit viper envenomation?

-pain
-weakness
-nausea
-salivation
-hypotension
-tachycardia
-tachypnea
-hyperthermia
-arrhythmias
-muscle fasciculations
-coma

How well did you know this?

Not at all

Perfectly

What are the clinical signs caused by neurotoxic rattlesnakes?

-depression
-weakness
-ataxia
-nystagmus

How well did you know this?

Not at all

Perfectly

What is the clinical pathology associated with pit viper envenomation?

CBC:
-increased PCV/TS
-leukocytosis
-echinocytosis
-thrombocytopenia

CHEM:
-inc. ALT, AST, CK
-hypokalemia

UA:
-hematuria
-myoglobinuria
-hemoglobinuria
-proteinuria

COAG:
-inc. PT and PTT
-hypofibrinogenemia

How well did you know this?

Not at all

Perfectly

What should be AVOIDED when treating pit viper envenomation?

-ice
-tourniquets
-incision/suction
-hot packs

How well did you know this?

Not at all

Perfectly

What are the components of initial pit viper envenomation patient evaluation?

-TPR
-blood pressure
-ECG
-baseline bloodwork
-fluid bolus

How well did you know this?

Not at all

Perfectly

What are the characteristics of treatment for pit viper envenomation?

-analgesia provided with opioids to start; NSAIDs once stable
-antibiotics contraindicated unless culture of drainage indicates otherwise; no prophylactic use
-antihistamines are not recommended
-glucocorticoids controversial; have anti-inflammatory effects but are also immunosuppressive and can interfere with anti-venom

How well did you know this?

Not at all

Perfectly

What are the characteristics of pit viper antivenom?

-binds/neutralizes venom toxins
-used in moderate to severe cases
-use dictated by cost and availability
-want to give early and repeat if re-envenomation occurs
-limits hematologic and neurologic progression

How well did you know this?

Not at all

Perfectly

How does severity of pit viper envenomation change the presentation and treatment?

mild cases:
-normal vitals
-localized bite, minimally progressive
-treated with fluids and monitoring for 8 to 24 h

moderate cases:
-slow ambulation and quiet mentation
-slowly progressive bite
-possible arrhythmia and/or coagulopathy
-treated with IV fluids and 2-4 vials of anti-venom

severe cases:
-recumbent/dull
-increased HR and weak pulses
-rapidly progressive bite
-treat with frequent/intensive monitoring, IV fluids, and 4-6+ vials of anti-venom

How well did you know this?

Not at all

Perfectly

What are the available pit viper anti-venom products in the US?

-antivenin crotalidae polyvalent (ACP)
-rattler antivenin, crotalidae
-venomvet

How well did you know this?

Not at all

Perfectly

What are the characteristics of anti-venom administration?

-dose ranges from 1 to 10 vials at a time
-each vial diluted in 100-150 mL of NaCl
-administered over 30 to 60 minutes
-can repeat q4-6h with re-envenomation

How well did you know this?

Not at all

Perfectly

What are the characteristics of hypersensitivity reactions to anti-venom?

-can cause vomiting, facial edema, pruritis, and urticaria
-pretreatment has questionable benefit
-can treat with diphenhydramine if reaction does occur

How well did you know this?

Not at all

Perfectly

What are the characteristics of anaphylaxis reactions to anti-venom?

-causes vomiting, resp. distress, and collapse
-treated with epinephrine

How well did you know this?

Not at all

Perfectly

What are the characteristics of serum sickness reactions to anti-venom?

-causes fever, nausea, dermatopathy, and joint swelling
-treated with glucocorticoids and supportive care

How well did you know this?

Not at all

Perfectly

What is the prognosis for pit viper envenomation?

-depends on severity and access to medical care
-local wounds have excellent prognosis
-mortality in dogs 1-30%
-mortality in cats 5-22%
-more fatalities with eastern diamondback rattlesnake bites

How well did you know this?

Not at all

Perfectly

What is the anatomy of coral snakes?

Study These Flashcards

-black face
-alternating black, yellow/white, and red pattern in which yellow touches red
-short, fixed front fangs
-round pupils
-no-heat sensing pits

What are the generalized effects of coral snake bites?

Study These Flashcards

-little local tissue reactions
-CNS depression
-muscle paralysis
-hypotension
-possible hemolysis

What are the clinical effects of coral snake bites in dogs?

Study These Flashcards

-CNS depression
-weakness
-hyperreflexia
-tremors
-delayed PLRs
-acute flaccid quadriplegia
-dyspnea/tachypnea
-resp. depression progressing to paralysis
-emesis
-salivation
-hypotension
-tachycardia

What are the clinical effects of coral snake bites in cats?

Study These Flashcards

-acute, ascending flaccid quadriplegia with maintained anal tone and micturition
-CNS depression
-vocalization
-anisocoria
-hypothermia
-resp. depression

What are the clin path findings with coral snake bites?

CBC: -possible anemia due to hemolysis -spherocytosis CHEM: -increased CK UA: -hemoglobinuria COAG: -normal PT/PTT -hyperfibrinogenemia

What should be avoided in coral snake bite treatment?

-incisions -ice -hot packs

What is the treatment for coral snake bites?

-compression bandage for bites on limb; keep in place until anti-venom given -hospitalization for 48h -mechanical ventilation -antibiotics for infection ONLY -no steroids -anti-venom in every case

What are the characteristics of coral snake anti-venom?

-always recommended -1 vial diluted in 100-250 mL of crystalloids and given over 30 minutes -initial dose is 2 vials; can repeat based on clinical response

What are the two main species of bufo toads in the US?

-colorado river toad -marine toad

When are bufo toads most active?

warmer months, especially after rainfall

What is the appearance of bufo toads?

-4 to 6 in.; possibly up to 9 in. -tan to reddish-brown, dark brown, or gray -large, triangular glands on dorsum of head and neck -no ridges/crests on top of head

What substances are released from the bufo toad parotid glands?

-dopamine -norepinephrine and epinephrine -serotonin -bufotenine -bufotoxins -bufagenins -indoalkylamines

What is important regarding the dose of bufo toad parotid gland substances?

the contents contained in both parotid glands is enough to be lethal to a 10 to 15 kg dog

What are the clinical effects of bufo toad toxicity?

-signs in 30 min. to 1 hr -hypersalivation -vomiting and diarrhea -hyperemic mm -pawing at mouth -tachypnea/dyspnea -ataxia -extensor rigidity -opisthotonos -seizures -coma -death -hyperthermia

What is the management for bufo toad toxicosis?

-oral rinsing every 10-15 minutes -endoscopy if toads are swallowed -IV fluids for cooling and CV support -seizure management -digoxin immune Fab fragments for cardiac arrhythmias

What are the characteristics of gila monsters?

-slow moving -will bite down and hold on -produce proteins and enzymes that cause clinical effects

What are the clinical effects of gila monster proteins/enzymes?

-profuse hemorrhage -pain -edema -ecchymoses -tachypnea/dyspnea -pulmonary edema -nausea -vomiting -diarrhea -salivation -tachycardia -hypotension -weakness -muscle fasciculations

What is the management for gila monster toxicosis?

-extraction of lizard -wound care; probe for fractured teeth -fluid therapy -analgesia -broad spectrum antibiotics -hyperbaric oxygen therapy

What are the characteristics of black widow spiders?

-produce funnel-shaped webs in dry, dimly lit, secluded spaces -males are unable to penetrate mammalian skin -females have a red or orange hourglass pattern on ventral abdomen

What are the characteristics of black widow envenomation?

-cats are more sensitive -1 bite can be lethal -venom contains alpha-latrotoxin neurotoxin

What are the clinical signs of black widow envenomation?

-peak effects at 24-48h with residual signs for weeks -numbness followed by hyperesthesia -muscle pain and fasciculations -muscle spasticity that progresses to flaccid paralysis -increased BP and HR -vocalization -vomiting and diarrhea -resp. distress -death from resp. paralysis or CV collapse

What is the treatment for black widow envenomation?

-lycovac antivenin; 1 vial over 30 min -benzodiazepines -opioids -fluids/supportive care

What is the prognosis for black widow envenomation?

-unknown for dogs -poor for cats

What are the characteristics of brown recluse venom?

-complex mixture of enzymes -contains a dermonecrotic agent -binding of cell membranes leads to neutrophil activation -causes rapid coagulation and capillary occlusion that leads to tissue necrosis -depletes clotting factors

What are the clinical signs of brown recluse envenomation?

-mild stinging up to 8 h; pruritus and pain -edema with "bullseye" lesion -hemorrhagic bullae that become eschars -sloughing of eschars to form indolent ulcers -eventual scarring

What is the treatment for brown recluse envenomation?

-treat as open wound -hyperbaric oxygen -supportive care -antibiotics -analgesics -aggressive surgery NOT reccommended

What are the clinical signs of arizona bark scorpion envenomation?

-vomiting -restlessness -lethargy -vocalizing -limping -head shaking -increases and decreases in HR and BP

What is the treatment for arizona bark scorpion envenomation?

-analgesics -BP and ECG monitoring -scorpion anti-venom

What are the clinical signs of walkingstick envenomation of the eye?

-irritation -lacrimation -corneal ulcers -ulcerative keratitis

What is the treatment for walkingstick envenomation of the eye?

-copious flushing of the eye -fluorescein stain and full ocular exam -antibiotics -artificial tears -possible atropine

What are the characteristics of hymenoptera?

-wasps, hornets, and yellow jackets can produce multiple venom-injecting stings -lethal dose is around 20 stings/kg -causes local pain and swelling -can cause anaphylaxis -can have delayed hypersensitivity; 3 days to 2 weeks

How is hymenoptera toxicosis managed?

-diphenhydramine -dexamethasone -epinephrine for anaphylaxis -BP and ECG monitoring -IV fluids -O2 +/- intubation/ventilation

Lecture 4 Flashcards

(52 cards)