Canis ISSN: 2398-2942

Carbamate poisoning

Synonym(s): Carbaryl, acetylcholinesterase inhibitor, methiocarb, toxicity, fungicide, herbicide

Contributor(s): Lisa Moore

Introduction

  • Cause: ingestion of insecticides, fungicides and herbicides derived from carbamic acid, thiocarbamic acid or dithiocarbamic acid, generally of low toxicity; mechanism of poisoning similar to organophosphate poisoning.
  • Signs: vomiting, tremor, convulsions.
  • Diagnosis: history, clinical signs.
  • Treatment: specific - atropine to effect; nervous signs - diazepam.
    The oximes, eg pralidoxime, are ineffective in carbamate poisoning.
    Do not administer barbiturates or other cardiorespiratory depressants.
  • See also organophosphate poisonings Organophosphorus poisoning.
  • Prognosis: excellent if treatment administered early enough.

Pathogenesis

Etiology

  • Carbamates, eg in fungicides and herbicides; in particular aldicarb, oxamyl, methiocarb, carbofuran, isolan, methomyl, formetanate, aminocarb, cloethocarb, bendiocarb, propoxur.
  • Vary in toxicity, generally considered relatively safe (note above exceptions).

Pathophysiology

  • Readily absorbed, fat soluble, diffuses readily into tissues.
  • The most toxic carbamates, eg aldicarb (LD50 = 5-10 mg/kg), carbofuran (LD50 = 19 mg/kg).
  • Block acetylcholinesterase (reversible) → accumulation of neurotransmitter acetylcholine → clinical signs; may → respiratory failure and death.

Timecourse

  • Most cases mild with rapid onset over minutes - hours within ingestion or exposure.
  • Death due to respiratory failure - a few hours to several days (depends on compound).
  • Occasionally rapidly fatal due to asphyxia.
  • Death may occur within a few hours to several days.

Diagnosis

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Tinson E, Boller E, Davis M (2017) A suspected case of intermediate syndrome in a dog with carbamate toxicosis. Aust Vet J 95 (6), 201-206 PubMed.
  • McEntee K, Poncelat L, Clerc X & Henroteaux M (1994) Acute polymyopathy after carbamate poisoning in a dog. Vet Rec 135 (4), 88-90 PubMed.
  • Fikes J D (1990) Toxicology of selected pesticides, drugs and chemicals - organophosphorus and carbamate insecticides. Vet Clin NA 20 (2), 353-367 PubMed.

Other sources of information

  • Lorgue G, Lechenet J & Reviere A (1966) Clinical Veterinary Toxicology. pp 66-68.

Organisation(s)


ADDED