ISSN 2398-2950      

Organophosphorus insecticide poisoning

ffelis

Synonym(s): Organophosphate toxicity, Organophosphate toxicosis


Introduction

  • Organophosphate insecticides (OPs) are commonly used pesticides.
  • Cause: ingestion of pesticide or following treatment for external parasites.
  • Action: organophosphates form a temporarily reversible bond with acetylcholinesterase (AChE) and butyrylcholinesterase (pseudocholinesterase), which becomes permanent with time.
  • Signs: cholinergic crisis (excessive parasympathetic stimulation, skeletal muscle stimulation and central stimulation) varying with the compound involved and individual susceptibility.
  • Treatment: prompt action requiring atropine and symptomatic support.
  • Prognosis: good if prompt treatment.

Pathogenesis

Etiology

  • Ingestion of liquid concentrates/granules of organophosphates/carbamate compounds (widely used for control of external parasites in dogs or control of insects in the home/garden) or from excessive skin or hair coat dusting or painting.
  • Ingestion of organophosphate insecticide-containing flea collars or cattle ear tags.

Pathophysiology

  • Organophosphate insecticides and carbamates are acetylcholinesterase enzyme inhibitors; organophosphates are irreversible inhibitors of the enzyme, whereas carbamates are reversible inhibitors of acetylcholinesterase.
  • Organophosphate compound  →  bond with acetylcholinesterase  →  inhibition of action of acetylcholinesterase  →  build-up of acetyl choline at the synapses and the neuromuscular junctions  →  stimulation of parasympathetic cholinergic synapses and neuromuscular junctions  →  eventual reduction in nerve sensitivity to stimulation causing depression  →  central respiratory depression, bronchial fluid accumulation and bronchoconstriction  →  asphyxia.

Timecourse

  • Signs develop within minutes or hours of exposure to organophosphate.
  • Time depends on individual susceptibility, compound, route of absorption and dose.

Diagnosis

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Fikes J D (1990) Toxicology of selected pesticides, drugs, and chemicals - organophosphorus and carbamate insecticides. Vet Clin North Am Small Anim Pract 20 (2), 353-367 PubMed.
  • Jaggy A & Oliver J E (1990) Chlorpyrifos toxicosis in two cats. J Vet Intern Med 4 (3), 135-139 PubMed.

Other sources of information

  • Talcott P A (2016) Organophosphorus and carbamate insectides. In: Blackwell's Five Minute Veterinary Consult. Small Animal Toxicology. 2nd edn. Hovda L, Brutlag A, Poppenga R, Petersen K (eds). Wiley-Blackwell, Ames, Iowa. pp 689-696.
  • Means C (2013) Organophosphate and carbamate insecticides. In: Peterson M E, Talcott P A Small Animal Toxicology. 3rd edn. St Louis, Missouri: Elsvier. pp 715-724.
  • Wismer T, Means C (2012) Toxicology of newer insecticides in small animals. Vet Clin Small Anim 42, 335-347.
  • Rosendale M E (2003) Disulfoton: a deadly threat to pets. Vet Med 98 (6), 466-469.
  • Osweiler G D (1995) Toxicology. Philadelphia: Williams and Wilkins. ISBN: 0 6830 6664 1.

Organisation(s)

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code