Exam 3 Flashcards
What is the most likely mechanism of pesticide exposure to animals and what type of animal is most likely affected and why?
oral
cats - likely liking products/ingesting
organophosphate
MOA
treatment
inhibits AChE
atropine or 2-PAM
oral & dermal decontamination
carbamates
MOA
treatment
inhibits AChE
atropine
oral & dermal decontamination
organochlorine (DDT & aryl hydrocarbons/cyclodienes)
MOA
treatment
DDT- slows Na influx & K efflux causing depolarization (more pronouced at temp <30 degrees C)
aryl hydrocarbons & cyclodienes inhibit GABA
NO antidotes - oral (activated charcoal & mineral oil) & dermal decontamination & anti-seizure meds
Pyrethrins & Pyrethroids
MOA
treatment
depolarization of excitable membranes via interaction with Na+ channels
NO antidotes - dermal decontaminations, methocarabmol & diazepam
alternatives include barbiturates, isoflurane or CRI propofol
Rotenone
MOA
treatment
inhibits oxidation of NADH to NAD+, inhibiting transfer of e- = decreased ATP
NO antidotes -symptomatic/supportive treatment (diazepam & glucose)
Fipronil (frontline)
MOA
treatment
inhibits GABA regulated Cl channels “pro-seizure”
symptomatic & supportive - dermal decontamination
Imidacloprid
MOA
treatment
HIGHLY SPECIFIC FOR INSECTS (esp bees) - neonicotinoid compound - acts on postsynapatic nicotinic R in CNS of insects “biphasic response”
low toxicity in mammals (a7 R) so symptomatic - dermal & oral decontamination
Ivermectin & Selamectin
MOA
treatment
hyperpolarization via binding to glutamate gated Cl- channels in invertebrates = paralysis & death & GABA agonist (which is resp for toxicity in mammals)
Physostigmine, symptomatic, oral decontamination, IV lipid emulsion
Amitraz
MOA
treatment
alpha-2 agonist
inhibits monoamine oxidase
atipamezole/yohimbine, diazepam, saline cathartics
contraindications: atropine, emesis and activated charcoal (due to ileus)
Metaldehyde
MOA
treatment
snails/slugs - torpid & dehydration
birds/mammals - poss due to metaldehyde/acetaldehyde crossing BBB & releasing 5-HT & NE
apomorphine, methocarbamol, diazepam/phenobarbital, fluids, bicarbonate
DEET
MOA
treatment
unknown MOA
diazepam/phenobarbital, dermal or GI decontamination
How does the persistent nature of organochlorine pesticides relate to their relevance as toxins to animals?
highly persistent in the environment and in organisms and bioaccumulate
What are the clinical signs for pyrethroid poisoning (in cats) and how do you treat pyrethroid poisoning in animals improperly treated with a spot-on product?
paresthesia
cats (when treated with dog products) - hypersalivation, paw shaking, ear, skin twitching, flicking of tail
higher doses = seizures
dermal decontamination - bathing + supportive care
What is the basis of the old adage “White Feet, Don’t Treat” with regards to the use of ivermectin as an anti-parasitic agent?
Collies show toxicity at low doses due to a mutation in mdr1 (PGP, ABCB1)
What are the treatment options for amitraz poisoning? What issues arise with regards to the use of anti-cholinergic therapies?
atipamezole & yohimbine
atropine is contraindicated due to hypertension & ileus
avoid activated charcoal due to ileus
Diethyltoluamide (DEET) is widely used as an insect repellant on humans. What are the issues regarding its’ use on pets or livestock?
toxicity is low, most animals recover quickly
limit toxicosis with < 50% deet