Felis ISSN 2398-2950

Paraquat poisoning

Contributor(s): Rosalind Dalefield

Introduction

  • Non-selective herbicide.
  • Signs: caustic damage to mouth and GIT:
    • Renal insufficiency and hepatic necrosis may be evident from 2-3 days after ingestion
    • Progressive dyspnea, 2-7 days after ingestion.
  • Treatment: no antidote.
  • Prognosis: very poor.

Pathogenesis

Etiology

  • Non-selective herbicide ingestion.
  • Used for aquatic weed control in UK.
  • Accidental poisoning rare.

Pathophysiology

  • Concentrated paraquat (20%) causes corrosive gastroenteritis.
  • Pulmonary toxicity caused by production of free radicals resulting in cell damage.
  • Paraquat is accumulated in lung tissue and renal tubular cells.
  • Results in pulmonary edema and terminal fibrosis; renal tubular necrosis; hepatocellular necrosis.
  • Increasing respired oxygen concentration may increase free radical generation.
  • Oxygen administration may contribute to pathology of pulmonary lesions.
  • Feline oral LD 50: 40-50 mg/kg.
  • High dose: may result in rapid multi-organ failure and death.
  • Lower dose: initial gastrointestinal signs followed by pulmonary fibrosis -progressive respiratory failure over days/weeks   →   death in <6 weeks.

Timecourse

  • Peak plasma concentration of paraquat within 75 minutes of ingestion (data from dogs).
  • Signs are progressive for up to 6 weeks after ingestion.

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.
  • Pond S M (1990) Manifestations and management of Paraquat poisoning. Medical J Aust 152 (5), 256-259 PubMed.
  • Hart T B, Nevitt A & Whitehead A (1984) A statistical approach to the prognostic significance of plasma paraquat concentrations. Lancet (8413), 1222-1223 PubMed.

Other sources of information

  • Thrall M A et al (2001) Ethylene glycol. In: Small Animal Toxicology. Eds: M E Peterson and P A Talcott. Philadelphia: W B Saunders. ISBN: 0 7216 7826 2.
  • Osweiler G D (1995) Toxicology. Philadelphia: Williams and Wilkins. ISBN: 0 6830 6664 1.
  • Lorgue G, Lechenet J & Riviere A (1996) Clinical Veterinary Toxicology. Oxford:Blackwell Science, pp97-98, 150. ISBN 0 632 03269 3.

Organisation(s)


ADDED