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Flashcards in Rodenticides/ Molluscicides Deck (48):
1

Zinc Phosphide is available or restricted

Most are restricted use pesticides

2

How much zinc phosphide is in the over the counter formulations

2-5%

3

Phine gas can be used as

fumigant for insects and rodents

4

Which two phosphide combinations have similar toxic effects to zinc phosphide

aluminum and magnesium

5

Exposure to zinc phoshide

- typically accidental ingestion
- caged birds can be poisoned by rodents tracking it in

6

What are the properties of zinc phosphide

- grey/black powder
- garlic or dead fish odor
- stable when dry but will decompose in environment after 2 weeks
- acid will liberate the phosphine gas
- not very water soluble

7

When is zinc phosphide acute and when is it chronic toxicity

- Acute due to gas release
- chronic with both zinc phosphide and phosphine gas

8

Lethal dose of zinc phosphide

- 20-40 mg/ kg
- 10-20 mg/ kg for caged birds

9

What body product will enhance zinc phosphine toxicity

- Acid/ gastric juice
- dogs that eat it on an empty stomach are more likely to survive

10

Toxicokinetics of zinc phosphide

- corrosive
- irritates GI
- inhalation of phosphine gas
- can see serum/ tissue zinc levels elevated
- not usually bad for skin absorption

11

How can you lower stomach pH to prevent liberation of phosphine gas

vomiting or increasing stomach pH to alkaline

12

MOA of zinc phosphide

- can inhibit oxidative phosphorylation = cell death
- ROS
- greatest effect on tissues with high oxygen demand
- damage to blood vessels and RBC
- late onset liver and kidney damage

13

Clinical signs of zinc phosphide

- anorexia, vomiting
- abdominal pain
- bloat in cattle
- increased RR, wheezing, dyspnea
- CNS excitation
- hypermotility, yelping, convulsions
- death in 3-48 hours

14

Lab results of zinc phosphide tox

- Need to be place in an airtight container and frozen ASAP
- metabolic acidosis
- dehydration
- hypocalcemia
- elevated zinc

15

Human precautions for Zinc Phosphide

- can detect at 2 ppm, but safe exposure is at 1ppm
- flammable

16

Treatment for zinc phosphide poisoning

- No antidote
- Warn owners to provide good ventilation to try to auto-decontaminate
- Can try: emetics, gastric lavage with dilute potassium permanganate, antacids
- supportive

17

Zinc phosphide poisoning prognosis

- auto-decontamination helps recovery
- if no signs by 8-12 hours or 12-24 hrs post vomiting = favorable
- severe signs = poor

18

Fluoroacetate chemical compound

sodium monofluoroacetate
compound 1080

19

How is fluoroacetate used

- live stock protection collar for controlling coyotes preying on sheep and goats
- pesticide in NZ and australia

20

Properties of fluoroacetate

- odorless
- water soluble
- insoluble in organic solvents
- degraded in soil
- irritant

21

Most and least toxicity to fluoroacetate (species)

- dogs are very sensitive
- LD50 of 0.06-0.2 mg/kg
- rodents are least sensitive

22

fluoroacetate toxicokinetics

- absorbed in the GI tract, lungs, or open wounds
- NOT though intact skin
- distribution throughout the body with no specific accumulation
- metabolite in urine
- can have relay toxicosis at high doses

23

MOA of fluoroacetate

- condenses with oxaloacetate to fluorocitrate
- competes with the citrate substrate in the Krebs cycle (citric acid, TCA)
- decreases cellular respiration and energy

24

What compound builds up due to fluoroacetate poisoning

- citrate
- its not being used by the TCA
- binds to calcium = hypocalcemia

25

Clinical signs of fluoroacetate poisoning in dogs

- rapid onset (30 min - 4 hours)
- GI signs
- running in a straight line, braking, yelping, seizures
- hyperthermia, mydriasis, coma
- death in 2-12 hours

26

What is tenesmus

the increased desire to evacuate the bowels

27

Clinical signs of fluoroacetate poisoning in horses

- Cardiac signs
- heart failure, staggering, arrhythmias
- colic and terminal convulsions
- death

28

Clinical signs of fluoroacetate poisoning in sheep

- disoriented running
- blindness
- weakness
- ataxia
- coma and death
- usually have concurrent copper and selenium def.

29

Clinical signs of fluoroacetate poisoning in cats and pigs

- bradycardia and arrhythmias
- depression or excitement
- vocalization
- hyperesthesia
- hypothermia

30

Lesions in fluoroacetate poisoning

rapid onset of rigor mortis

31

Lab results from fluoroacetate poisoning

- Chem on GI contents
- elevate citrate levels
- hyperglycemia
- metabolic acidosis
- low ionized calcium

32

Treatment for fluoroacetate poisoning

- rapid onset so often don't get to treat
- emesis and activated charcoal
- Acetate donors: glycerol monoacetate, acetic acid/ ethanol, acetamide/ dextrose

33

Prognosis for fluoroacetate poisoning

guarded to grave

34

Molluscicide

Methaldehyde

35

Use of metaldehyde

- restricted use pesticide
- fuel for camp stoves

36

Typical exposure to metaldehyde

- ingestion of bait
- malicious poisoning

37

Properties of metaldehyde

- irritant
- flammable
- poorly soluble in water
- products can release chemical for 10-14 days in moist conditions

38

Metaldehyde toxicity gradient in species

- dogs, cats, livestock and horses are susceptible
- cats more sensitive
- dogs more likely to ingest

39

metaldehyde is more toxic when

- inhaled
- ingestion is the more common route though

40

Which species is endangered to to metaldehyde

hedgehogs (feed on snails and slugs)

41

Metaldehyde toxicokinetics

- readily absorbed from GI tract
- undergoes acid hydrolysis
- can cross the BBB
- metabolized by the liver
- can undergo recirculation

42

Metaldehyde MOA

- Decreases brain GABA (seizures)
- GI irritation
- metabolic acidosis
- hyperthermia due to CNS excitation

43

Metaldehyde clinical signs

- Acute nurotoxicosis and hyperthermia (shake and bake)
- onset in 3 hours
- salivation, vomiting, diarrhea
- incoordination, muscle tremors, hyperesthesia, seizures
- cats= nystagmus and mydriasis
- reversible blindness in dogs

44

Animals may recover from Metaldehyde poisoning in

2-3 weeks

45

Lesions with metaldehyde poisoning

- formaldehyde odor of stomach contents
- petechiae in GI mucosa
- congestion, edema, hemorrhage in lungs, liver and kidney

46

Lab results for metaldehyde poisoning

- detection of metaldehyde in stomach, bait, serum, urine or liver tissue

47

Treatment for metaldehyde

- no specific antidote
- emetics, gastric lavage, activated charcoal, enemas
- fluid therapy
- managing hyperthermia, seizures

48

Prognosis with metaldehyde poisoning

- Survive first 24 hrs = good
- can have post recovery liver failure