Rodenticides

Question 1

Rodenticides

Answer 1

Sources: pastes, pellets, concentrate mixes, tracking powders
Anticoagulants, cholecalciferol, bormethalin

Question 2

First gen anticoagulants

Answer 2

Requires longer or multiple exposure feedings, shorter duration
Ex: warfarin (t1/2- 14 hours), pindone, dicomarol

Question 3

Second gen anticoagulants

Answer 3

Single feeding required with long duration
Ex: diphacinone, brodifacoum and bromadiolone

Question 4

2 major chemical types of anticoagulants

Answer 4

1. Courmarins (warfarin/final, brodifacoum/havoc and bromadiolone)
2. Indanediones (pindone/ pivalyn, diphacinone/ ramik, chlorphacinone)

Question 5

Warfarin PK

Answer 5

A: >90%
D: high protein binding
M: MFO –> inactivated hydroxylated metabolites
E: liver and kidney

Question 6

Warfarin mechanism

Answer 6

Completely inhibits Vit. K epoxide reductase
Final carboxylation and activation of clotting Vit. K dependent factors (1,2,7,9,10)

Question 7

Anticoagulant adverse effects

Answer 7

Hemorrhage: @ pressure points
Sudden internal hemorrhage: dead no signs
Prolonged bleeding
CVS effects (hematoma, epistaxis, dark tarry stool)

Question 8

Anticoagulant treatment

Answer 8

Activated charcoal and catharsis
Whole blood transfusion
Antidote: Vit. k1 in dogs and cats (IM/SC/PO)

Question 9

Cholecalciferol (Vit. D3)

Answer 9

Causes delayed death 1-3 days with single feeding
From supplements for animals, humans and feed additives

Question 10

Cholecalciferol mechanism

Answer 10

Increase Ca++ absorption in intestinal mucosa
Stimulates Ca++ binding protein synthesis
PTH increases osteoclastic activity
Increase Ca++ reabsorption in renal tubules

Question 11

Cholecalciferol toxicosis

Answer 11

12-36 hours post consumption
PU/PD, petechial hemorr, pale streaks in renal tube
Hypercalcemia, soft tissue mineralization, cellular degeneration and necrosis

Question 12

Cholecalciferol detoxification

Answer 12

Emesis, gastric lavage or charcoal
Diuretics

Question 13

Cholecalciferol fluid therapy

Answer 13

Prednisone
Pamidronate (inhibit osteoclasts)
Salmon calcitonin (reduce serum Ca++)

Question 14

Manchester wasting disease: Enzootic hypercalcemia

Answer 14

Ruminants and horses
From Solanum malacoxylum
Extensive calcification of soft tissues

Question 15

Bromethalin mechanism

Answer 15

Uncouples oxidation phosphylation –> loss of NaKATPase –> intracellular swelling, edema and lipid peroxidation

Question 16

Bromethalin toxic effects

Answer 16

Cerebral edema, ataxia, muscle tremors, hyperexcitability, lipid peroxidation, paddling

Question 17

Bromethalin treatment

Answer 17

Supportive: mannitol, dexamethasone, fluids
Diazepam, phenobarbitol

Question 18

Strychnine

Answer 18

From gopher bait and ground squirrels and control predators
Inhibits glycine at Renshaw cells, stimulates extensor muscle and hypertonicity of resp. muscles

Question 19

Strychnine clinical toxicosis

Answer 19

Nervousness, restlessness, muscle tremors, muscle tics response to noise or bright light
Tetanic seizures, saw horse stance, myoglobinuria

Question 20

Strychnine poisoning treatment

Answer 20

Pentobarbital
Muscle relaxers: methocarbamol, glyceral guiaicolate
Gastric lavage, charcoal, fluid diuresis

Question 21

Phosphides (Zn, Al, Ca)

Answer 21

Exposure from rodent baits, malicious baiting and phosphine gas
Toxicity increases with full stomach

Question 22

Phosphides toxicokinetics

Answer 22

Stomach acid hydrolyzes Phosphide salts –> Phosphide –> readily cross mucous membrane

Question 23

Phosphides mechanism

Answer 23

Resp. and GIT irritation
Inhibits cytochrome C oxidase
Lethal: 20-50 mg/kg

Question 24

Phosphides CS

Answer 24

Acute clinical onset
CNS: seizures, tremors, running, weakness
Large animals: colic and bloat
Acidosis, hyperphosphotemia, hypoglycemia
Lesions: SC–> acetylene/ dead fish odor

Question 25

Phosphides treatment

Answer 25

Bicarbonate and supportive: GIT protectants and monitoring

Question 26

Fluoroacetamides Compound 1080 and 1081

Answer 26

Source: pellets, licensed exterminators, predator collars Targets CNS, CVS, GIT Dose: small doses very toxic

Question 27

Mechanism for Fluoroacetamides

Answer 27

Inhibits aconitase enzyme Blocks energy production and respiration Prominent in dogs

Question 28

Fluoroacetamides treatment

Answer 28

Charcoal Glycerol monoacetate Ethanol (50%) and acetic acid (5%) Supportive: barbituates, ventilation/ O2 therapy, antiarrythmics

Question 29

Yellow phosphorus

Answer 29

Strong oxidizer Emits green light and white fumes (glows in the dark)

Question 30

Yellow Phosphorus mechanism

Answer 30

Protoplasmic poison Fatty degeneration in liver, kidney and brain Strong irritant--> necrotizing effect in stomach mucosa

Question 31

Yellow Phosphorus clinical toxicosis

Answer 31

Violent vomiting/ diarrhea Icterus, hemorrhagic lesions, shock Garlic odor breath Necrosis of liver and renal PT