Insecticides Flashcards
Describe the toxicity of Pyrethins and Pyrethroids
who is susceptible
- low toxicity in mammals
- cats more sensitive than dogs
- very toxic to fish and birds
Describe the toxicokinetic features of Pyrethins and Pyrethroids
- unstable in air and light
- lipid soluble
- rapidly metabolized in GIT, plasma, and liver
- do not accumulate in tissues
How can animals get exposed to Pyrethins and Pyrethroids?
- dermal exposure most common
- ingestion and inhalation possible
What is the mechanism of action of Pyrethins and Pyrethroids?
- delay closure of Na channels in axonal membrane of insect
- “knock down” effect: rapid paralysis
- may inhibit ATPase leading to repetitive firing
What are the clinical signs of Pyrethin and Pyrethroid toxicosis?
- generalized muscle tremors, depression, blindness, ataxia
- salivation, vomiting, diarrhea, hyperexcitability
- may progress to seizures, dyspnea, and death
What is the treatment of Pyrethin and Pyrethroid toxicosis?
- wash skin with soap/water
- monitor and control temp
- symptomatic treatment (treat seizures)
What are the toxicokinetic features of DEET?
- absorbed from skin and GI tract
- metabolized in liver
- excreted in urine
What are the clinical signs of DEET toxicosis?
- rabbits/rats: depression, excitation, ataxia, tremors, seizures, coma
- dogs/cats: salivation, vomiting, hyperexcitability, tremors, ataxia, seizures
What is the treatment for DEET toxicosis?
- if dermal, wash with soap/water
- emesis, activated charcoal with cathartic
- symptomatic treatment
What is Amitraz, and what is it used for?
- foramidine insecticide/acaracide
- paralyzes mouth parts of mites and ticks
What is the mechanism of action of Amitraz?
- alpha-2 adrenergic agonist in CNS
- weak alpha-1 agonist and MAO inhibitor
What are the toxicokinetic features of Amitraz?
- absorbed orally, or inhalation and dermal
- well distributed throughout body and CNS
- metabolized by liver
- excreted in urine
What are the clinical signs of Amitraz toxicosis?
- transient sedation most common
- lethargy, bradycardia, ataxia, depression, vomiting, dyspnea, hypothermia, tremors
- can cause CV collapse and resp failure
- hyperglycemia
How is Amitraz toxicosis treated?
- antidote: alpha-2 antagonists (Yohimbine, Atipamezole)
- wash skin with soap/water
- if collar ingested, emesis or activated charcoal
- supportive care
Who is most susceptible to ivermectin toxicosis?
- dogs and small birds
- collie breeds
