Unit 2 - Venoms and Poisons I

Question 1

What are biotoxins?

Answer 1

Toxins of biological origin

Question 2

What are the two primary functions of biotoxins?

Answer 2

Offense/predation

Defense

Question 3

What are the three types of biotoxins?

Answer 3

Hemotoxins
Neurotoxins
Cytotoxins

Question 4

What do hemotoxins cause?

Answer 4

Hemolysis, thrombosis, and thrombolysis

Question 5

What do neurotoxins affect?

Answer 5

The nervous system of affected animals

Question 6

At what level are cytotoxins toxic (biologically)?

Answer 6

At the cellular level either non-specifically or in certain cells

Question 7

What does venomous mean?

Answer 7

Producing a toxin in a highly specialized secretory gland or group of cells and the toxin is delivered during biting or stinging

Question 8

What does poisonous mean?

Answer 8

A toxin accumulates in various body parts and poisoning occurs via ingestion

Question 9

T/F: A poisonous toxin can be delivered purposefully.

Answer 9

False

Question 10

What are offensive venoms oriented towards?

Answer 10

Predation and feeding

Question 11

What are offensive venoms generally associated with anatomically?

Answer 11

The oral pole

Question 12

What are defensive venoms associated with anatomically?

Answer 12

The aboral pole

Question 13

What are the characteristics of venoms?

Answer 13

They often are high molecular weight proteins, have enzymatic properties, and have more than one action

Question 14

What are the characteristics of poisons?

Answer 14

Less likely to be proteins and are usually absorbed via the GI tract

Question 15

What are the general classes of venomous species?

Answer 15

Reptilia, Arachnida, and Hymenoptera

Question 16

What reptilia families are venomous?

Answer 16

Snakes - Viperidae, Elapidae

Lizards - Heloderma

Question 17

What arachnida species/insects are venomous?

Answer 17

Black widow, brown recluse, and scorpions

Question 18

What hymenoptera insects are venomous?

Answer 18

Bees, wasps, and ants

Question 19

What snakes of the Elapidae family are venomous?

Answer 19

Cobra, Coral, and sea snakes

Question 20

What snakes of the Viperidae family are venomous?

Answer 20

Rattlesnakes, copperhead, cottonmouth, bush vipers, and puff adder

Question 21

What are the general characteristics of venomous snakes?

Answer 21

Poikilothermic, carnivorous, difficulty seeing stationary objects, detect movement via ground vibration, and have posteriorly curved teeth

Question 22

What are proteroglyphs?

Answer 22

Snakes with shortened maxillae and a few teeth

Fangs have a venom groove, often on the front

Question 23

What are solenoglyphs?

Answer 23

Snakes with the smallest maxilla but support very large, mobile fangs
They can open their mouth to almost 180 degrees

Question 24

How do solenoglyphs deliver venom?

Answer 24

Via needle-like, tubed channel; they have mobile fangs

Question 25

What allows snakes to hinge their jaw and swallow prey much larger than their head?

Answer 25

The quadrate bone | Their mandibular symphysis is also formed by an elastic ligament

Question 26

Where are the fangs located in elapidae?

Answer 26

At the anterior end of the maxilla; they are deeply grooved and fixed

Question 27

Coral snakes are _____ ft. in body length. Venom dose (increases/decreases) with length. Envenomation requires a _______ action due to the poorly developed venom delivery system.

Answer 27

3-4ft increases chewing

Question 28

What does coral snake venom contain?

Answer 28

Neurotoxic polypeptides - non-depolarizing, irreversible binding Enzymes - phospholipase A

Question 29

When is the onset of clinical signs for coral snake envenomation?

Answer 29

It may be delayed for up to 12 hours

Question 30

What is the MOA of coral snake venom?

Answer 30

Post-synaptic neuromuscular blockade that lasts for 36-48 hours

Question 31

What clinical signs are associated with coral snake envenomation?

Answer 31

``` Ascending flaccid paralysis Hypotension CNS depression Salivation Tachycardia +/- hemolysis ```

Question 32

What is death associated with coral snakes due to?

Answer 32

Respiratory failure

Question 33

What lesions are associated with coral snake bites?

Answer 33

Small puncture wounds | Bleeding with minimal tissue swelling

Question 34

What CBC/Chemistry changes are associated with coral snake bites?

Answer 34

``` Hematuria Hemoglobinuria Myoglobinemia Elevated CPK Elevated Alkaline phosphatase Anemia +/- spherocytes ```

Question 35

T/F: Spherocyte production due to coral snake envenomation is dose dependent. The direct effect of venom is IMHA.

Answer 35

False - Spherocyte production is dose dependent, but the direct effect is on erythrocyte membranes and not IMHA

Question 36

When does peak spherocytosis due to coral snake envenomation occur?

Answer 36

Around 5 days post-envenomation

Question 37

How is coral snake envenomation treated?

Answer 37

Close observation - may require ventilator support due to potential respiratory paralysis Antivenin is no longer available

Question 38

Why are pit vipers called pit vipers?

Answer 38

They have a heat-sensing pit located between the eye and nostril on each side of the head

Question 39

How fast is the strike speed of pit vipers?

Answer 39

8 feet per second

Question 40

Describe the characteristics of rattlesnakes.

Answer 40

Most, but not all, sound off before striking with their keratin rattles in their crotalid tails Their fangs are hollow and retractable

Question 41

How do rattle snakes envenomate?

Answer 41

The rotate and inject venom in a stabbing motion

Question 42

What are the components of rattlesnake venom?

Answer 42

Cytotoxins, neurotoxins, cardiotoxins, hemolysins, coagulants, anticoagulants, collagenases, kallikrein-like compounds Hyaluronidase

Question 43

What does the kallikrein activity of rattlesnake venom lead to the formation of?

Answer 43

Bradykinin and plasmin

Question 44

T/F: Not all bites of rattlesnakes result in envenomation

Answer 44

True

Question 45

Why don't all rattlesnake bites result in envenomation?

Answer 45

It takes approximately 21 days for vipers to replenish venom so if they bit something recently then they might not have produced any venom

Question 46

How can you differentiate between a dry and a wet rattlesnake bite?

Answer 46

If there are no signs in 8 hours it is likely a dry bite

Question 47

What clinical signs are associated with rattlesnake envenomation?

Answer 47

Local pain and swelling initially Elevated temperature Petechiation, ecchymosis, and skin discoloration Hypotension and shock may develop in 3-36 hours With time - continued swelling, pain, hemorrhage, tissue necrosis, and sloughing of tissue

Question 48

What species are most often affected by rattlesnakes?

Answer 48

Dogs

Question 49

What other species are affected by rattlesnake bites?

Answer 49

Horses and camelids, cattle, and cats

Question 50

When do rattlesnake bites typically occur in dogs? | Where are the most common sites of rattlesnake bites in dogs?

Answer 50

May to September | Head and front legs are the most common sites

Question 51

Where are the most common sites of rattle snake bites in horses and camelids?

Answer 51

Bites are most often on the muzzle; lower limbs less so

Question 52

Where are the most common sites of rattlesnake bites in cattle?

Answer 52

Tongue and muzzle

Question 53

T/F: Cats are more resistant to pit viper venom.

Answer 53

True

Question 54

Where are the most common sites of rattlesnake bites in cats?

Answer 54

On the torso

Question 55

What CBC/Chemistry abnormalities are associated with rattlesnake envenomation?

Answer 55

Hemolysis Type III echinocytes Hypoproteinemia Elevated CPK

Question 56

What coagulation profile abnormalities are associated with rattlesnake envenomation?

Answer 56

Increased PT, PTT, and FDP | Thrombocytopenia

Question 57

What urinalysis abnormalities are associated with rattlesnake envenomation?

Answer 57

Hematuria and myoglobinuria

Question 58

What is the rattlesnake bite severity scoring system used to do?

Answer 58

ID high-risk cases and to provide objective patient assessment during treatment over time

Question 59

What variables determine the rattlesnake bite severity score?

Answer 59

``` Respiratory system CV system Wound scoure GI system Hematologic system CNS ```

Question 60

What variables determine rattlesnake bite severity in horses?

Answer 60

Respiratory scores CV scores Wound scores Hemostasis score

Question 61

A RBSS score of ___ or greater is often associated with a poorer prognosis in horses.

Answer 61

8

Question 62

How is rattlesnake envenomation treated?

Answer 62

Keep animal quiet and try to keep bite area below heart level Supportive care Antivenin

Question 63

What supportive care is recommended for rattlesnake envenomation?

Answer 63

IV fluid, analgesics, and blood product therapy

Question 64

What may the antivenin for rattlesnakes reverse? What won't it reverse?

Answer 64

Reverse - coagulopathy, thrombocytopenia, and paralysis | Not reverse - tissue necrosis, renal damage, etc.

Question 65

What is the general protocol for rattlesnake treatment?

Answer 65

1. Animals with known or suspect snakebites should be hospitalized and monitored for a minimum of 8 hours 2. RBSS should be performed at admission 3. Antivenin should be administered immediately if indicated/desired 4. RBSS is repeated at 6 hours to determine any worsening of score 5. If no signs at 8 hours, likely a dry bite 6. If conditions worsen, treat as clinical signs dictate

Question 66

How is rattlesnake envenomation prevented?

Answer 66

Know where the are located geographically Avoidance training Toxoid vaccine for high-risk patients

Question 67

How do venomous lizards bite?

Answer 67

Tenacious bite - deliver venom from glands in the lower jaw by aggressive chewing action over grooved teeth

Question 68

What bad agents are in lizard venom?

Answer 68

Gilatoxin and hyaluronidase

Question 69

Where do lizards typically bite?

Answer 69

Usually on the face, especially lower lip

Question 70

What clinical signs are associated with venomous lizard bites?

Answer 70

Very painful bite site - bleeding and localized swelling Hypotension and tachycardia Vomiting

Question 71

How is lizard envenomation treated?

Answer 71

Remove lizard - pry it or apply a heat/flame source underneath the jaw Inpatient - monitor and treat hypotension with crystalloid fluids as needed

Question 72

In regards to coral snakes. Red to yellow, _______ _ ______. Red to black, ________ _______.

Answer 72

Kill a fellow | Venom lack