Rodenticides Flashcards
Rodenticides
Sources: pastes, pellets, concentrate mixes, tracking powders
Anticoagulants, cholecalciferol, bormethalin
First gen anticoagulants
Requires longer or multiple exposure feedings, shorter duration
Ex: warfarin (t1/2- 14 hours), pindone, dicomarol
Second gen anticoagulants
Single feeding required with long duration
Ex: diphacinone, brodifacoum and bromadiolone
2 major chemical types of anticoagulants
- Courmarins (warfarin/final, brodifacoum/havoc and bromadiolone)
- Indanediones (pindone/ pivalyn, diphacinone/ ramik, chlorphacinone)
Warfarin PK
A: >90%
D: high protein binding
M: MFO –> inactivated hydroxylated metabolites
E: liver and kidney
Warfarin mechanism
Completely inhibits Vit. K epoxide reductase
Final carboxylation and activation of clotting Vit. K dependent factors (1,2,7,9,10)
Anticoagulant adverse effects
Hemorrhage: @ pressure points
Sudden internal hemorrhage: dead no signs
Prolonged bleeding
CVS effects (hematoma, epistaxis, dark tarry stool)
Anticoagulant treatment
Activated charcoal and catharsis
Whole blood transfusion
Antidote: Vit. k1 in dogs and cats (IM/SC/PO)
Cholecalciferol (Vit. D3)
Causes delayed death 1-3 days with single feeding
From supplements for animals, humans and feed additives
Cholecalciferol mechanism
Increase Ca++ absorption in intestinal mucosa
Stimulates Ca++ binding protein synthesis
PTH increases osteoclastic activity
Increase Ca++ reabsorption in renal tubules
Cholecalciferol toxicosis
12-36 hours post consumption
PU/PD, petechial hemorr, pale streaks in renal tube
Hypercalcemia, soft tissue mineralization, cellular degeneration and necrosis
Cholecalciferol detoxification
Emesis, gastric lavage or charcoal
Diuretics
Cholecalciferol fluid therapy
Prednisone
Pamidronate (inhibit osteoclasts)
Salmon calcitonin (reduce serum Ca++)
Manchester wasting disease: Enzootic hypercalcemia
Ruminants and horses
From Solanum malacoxylum
Extensive calcification of soft tissues
Bromethalin mechanism
Uncouples oxidation phosphylation –> loss of NaKATPase –> intracellular swelling, edema and lipid peroxidation
Bromethalin toxic effects
Cerebral edema, ataxia, muscle tremors, hyperexcitability, lipid peroxidation, paddling
Bromethalin treatment
Supportive: mannitol, dexamethasone, fluids
Diazepam, phenobarbitol
Strychnine
From gopher bait and ground squirrels and control predators
Inhibits glycine at Renshaw cells, stimulates extensor muscle and hypertonicity of resp. muscles
Strychnine clinical toxicosis
Nervousness, restlessness, muscle tremors, muscle tics response to noise or bright light
Tetanic seizures, saw horse stance, myoglobinuria
Strychnine poisoning treatment
Pentobarbital
Muscle relaxers: methocarbamol, glyceral guiaicolate
Gastric lavage, charcoal, fluid diuresis
Phosphides (Zn, Al, Ca)
Exposure from rodent baits, malicious baiting and phosphine gas
Toxicity increases with full stomach
Phosphides toxicokinetics
Stomach acid hydrolyzes Phosphide salts –> Phosphide –> readily cross mucous membrane
Phosphides mechanism
Resp. and GIT irritation
Inhibits cytochrome C oxidase
Lethal: 20-50 mg/kg
Phosphides CS
Acute clinical onset
CNS: seizures, tremors, running, weakness
Large animals: colic and bloat
Acidosis, hyperphosphotemia, hypoglycemia
Lesions: SC–> acetylene/ dead fish odor
Phosphides treatment
Bicarbonate and supportive: GIT protectants and monitoring
Fluoroacetamides Compound 1080 and 1081
Source: pellets, licensed exterminators, predator collars
Targets CNS, CVS, GIT
Dose: small doses very toxic
Mechanism for Fluoroacetamides
Inhibits aconitase enzyme
Blocks energy production and respiration
Prominent in dogs
Fluoroacetamides treatment
Charcoal
Glycerol monoacetate
Ethanol (50%) and acetic acid (5%)
Supportive: barbituates, ventilation/ O2 therapy, antiarrythmics
Yellow phosphorus
Strong oxidizer
Emits green light and white fumes (glows in the dark)
Yellow Phosphorus mechanism
Protoplasmic poison
Fatty degeneration in liver, kidney and brain
Strong irritant–> necrotizing effect in stomach mucosa
Yellow Phosphorus clinical toxicosis
Violent vomiting/ diarrhea
Icterus, hemorrhagic lesions, shock
Garlic odor breath
Necrosis of liver and renal PT
