Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RUSVM Toxicology Summer 2019 > Zootoxins (Bufo Toad and Snake Venom) (Shokry) > Flashcards

Zootoxins (Bufo Toad and Snake Venom) (Shokry) Flashcards

1
Q

What are the toads in the Bufo family?

A
  • Cane or marine toad
  • Colorado river toad
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What toxins does the Bufo toad carry?

A
  • Catecholamines (dopamine, norepinephrine, epinephrine) and serotonin
  • Bufotenine
  • Bufogenins
  • Bufotoxins
  • Indole alkylamines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where are the bufo toad toxins stored in the animal?

A

Parotid glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What toxin from toads is a Schedule I substance because it has an hallucinogenic effect?

A
  • Bufotenine
  • Indole alkylamines are similar to the hallucinogen LSD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What’s unique about bufagenins and bufotoxins?

A

Cardioactive steroids similar to digitalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What species are most suspecptible to Bufo toad intoxication?

A

Dogs

  • Cats and ferrets can also be poisoned
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the most common season and time for bufo toad intoxication?

A
  • Summer season
  • Evening (most toads are nocturnal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What’s the toxic dose of bufo toads?

A

1 mg/kg of secretions cause poisoning signs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where are Bufo toxins absorbed and distributed?

A

Mucous membranes of mouth, gastric mucosa, conjunctiva, and open skin wounds and distributed all over body (including CNS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the MOA of Bufo toad intoxication?

A
  • Direct irritation of mucus membranes
  • Main organs affected: heart, blood vessels, and CNS
  • Bufotenine and bufotoxins → digitalis-like effect by inhibiting Na/K-ATPase
  • Indole alkylamines → hallucinogenic
  • Bufotenine → vasoconstriction and hallucinogenic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the clinical signs associated with Bufo toad intoxication?

A
  • Irritation of oral mucosa (hypersalivation [foaming], brick red mucous membranes, vocalization and vomiting)
  • Neurological signs (disorientation, ataxia, circling, seizures, opisthotonos, hyperthermia, and coma)
  • Cardiovascular (tachypnea, tachycardia, cardiac arrhythmia, or bradycardia and collapse)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Are there lesions associated with Bufo toad intoxication?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

↑ in hemoglobin content, PCV, blood glucose, BUN, alkaline phosphatase, serum potassium, calcium, and phosphorous are consistent with what zootoxin?

A

Bufo toad toxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the DDX for bufo toad intoxication?

A

Disease causing seizure, cardiac toxicity, caustic, and hyperthermia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

DDX for diseases/toxins causing seizures?

A
  • Bufo toad toxin
  • Metaldehyde
  • Theobromine
  • Cholinesterase inhibitor
  • Idiopathic epilepsy
  • Infectious meningioencephalitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What toxins can cause cardiac toxcity?

A
  • Bufo toxin
  • Digitalis toxicity
  • Poisonous plant with cardiac glycosides (gossypol or oleander)
17
Q

DDX for toxins that are caustic?

A
  • Bufo toxin
  • Acids/alkalis
  • Detergents
  • Bleaches
18
Q

What is the treatment for bufo intoxication?

A
  • Flush mouth with running water
  • Activated charcoal
  • Seizures: diazepam, phenobarbital, propofol, glucocorticoid, furosemide, and mannitol
  • Atropine (bradycardia, as bronchodilator, and decrease secretions [contraindicated w/ tachycardia])
  • Tachycardia/arrhythmia (B blocker, lidocaine/procainamide for ventricular)
  • Digoxin (may bind bufagenins and bufotoxins)
  • Supportive therapy (fluid therapy, famotidine [H2 blocker for caustic toxin effect])
19
Q

What are the poisonous snakes of North America?

A
  • Pit vipers, Crotalid family
  • Coral snakes
20
Q

What are the pit vipers?

A
  • Rattlesnake
  • Copperhead
  • Cottonmouth, water moccasins
21
Q

What are the general characteristics of pit vipers?

A
  • Have temp sensitive pit between eyes and nostrils
  • Broad, triangular head
  • Vertical pupils with prominent ellipitical slits
  • Retractable fangs of upper jaw
22
Q

What toxins are in snake venom?

A

Combination of enzymatic and nonenzymtic proteins and amino acids

  • Nonenzymatic proteins and peptides are “killing fraction”
23
Q

What species is most susceptible to snake venom? Which is most sensitive?

A
  • Dogs are most susceptible (also cats and horses)
  • Dogs are most sensitive (but cats more severely affected)
24
Q

What are the sources for pit vipers?

A

ALL US STATES (except Maine, Aslaska, and Hawaii)

  • Most bites due to Copperheads
25
Q

Of the pit vipers, which are the most toxic?

A

Rattlesnake > cottonmouth > copperhead

  • Severity depends on venom potency, amount, and season (April-October)
26
Q

What is the MOA of snake venom?

A

PRIMARY effect is hypocoagulation

  • Hyalurondiase cause venom to spread
  • Phospholipase A2 disrupt cell membranes, uncouples oxidative phosphorylation, and releases vasoactive amines
  • Enzymatic and nonenzymatic proteins have hematoxic (procoagulant, anticoagulant ), cardiotoxic, and neurotoxic effects
27
Q

What are the clinical signs of pit viper envenomation?

A

Envenomatous

  • Ecchymosis
  • Puncute worund
  • Fang mark
  • Bleeding
  • Edema
  • Swelling
  • Petechia
  • Necrosis

Nonenvenomatous

  • Mild local signs
  • No systemic signs
  • Normal laboratory findings
28
Q

How long does it take to see pit viper clinical signs?

A

Onset may be rapid or delayed for several hours

29
Q

Lab shows echinocytosis, hemolysis, hemoconcentraiton, increased or decreased coagulation time, hypokalemia, and liver and renal failure. What zootoxin is this consistent with?

A

Pit viper envenomation

30
Q

How is snake venom toxin detection in tissues?

A

Not practical

31
Q

Treatment for snake envenomation?

A

ANIMAL NEEDS TO BE IMMOBILIZED

  • First aid: keep calm, keep bite below level of heart, monitor swelling, avoid incision and suction of bite site to decrease venom absoprtion
  • Polyvalent crotalid antivenin: available for dogs, can cause allergic reaction (antiphylactoid therapy)
  • Diphenhydramine IV: reduce allergic rxn to antivenin and sedates
  • Fluid therapy
  • Blood transfusion
  • Broad-spectrum antibiotics
  • Control pain with fentanyl
  • Maintain airway and treat shock
32
Q

What is contraindicated in pit viper treatment?

A

Corticosteroids and NSAIDs

33
Q

T/F: if your dog gets a snake bite but has the rattle snake vaccine, you do not need to bring it in to be treated

A

False Still considered an medial emergency

34
Q

What are the characteristics of coral snakes?

A
  • Black head with alternating bands of black, yellow (or white) and red
  • Small head with rounded pupils
  • Short fixed front fangs
  • Require chewing action to inject venom
35
Q

What is the MOA of coral snake envenomation ?

A
  • Local tissue rxn and destruction by hyaluronidase, proteinase, ribonuclease, desoxyribonuclease, and phospholipase
  • Primary effect is neurotoxic
  • Nondepolarizing neuromuscular blockade, CNS depression, muscle paralysis, and vasomotor activity
  • Hemolysis with severe anemia and hemoglobinuria reported in dog
36
Q

Clinical signs with coral snake envenomation ?

A
  • CNS depression, quadriplegia with decreased spinal reflexes, respiratory paralysis, hypotension, and ventricular tachycardia
  • Dogs also can have hemolysis, anemia, hemoglobinuria, and may salivate excessively (not seen in cat)
  • Aspiration pneumonia can be a complication
37
Q

Elevated fibrinogen and CK RBC morphological changes, anemia, and hemoglobinuria What zootoxin is this associated with?

A

Coral snake envenomation

38
Q

What is your dddx for coral snake envenomation ?

A
  • Tick paralysis
  • Botulism
  • Myasthenia gravis
39
Q

Treatment for coral snake envenomation ?

A
  • Micrurus fulvius antivenin
  • Life support and symptomatic therapy as in pit vipers

RUSVM Toxicology Summer 2019 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions