Felis ISSN 2398-2950

Bromethalin poisoning

Contributor(s): Rosalind Dalefield, Nicola Bates

Introduction

  • Rodenticide poison produced as grain-based bait or pellets.
  • Signs: neurological signs with seizures.
  • Diagnosis: signs and post-mortem demonstration of bromethalin or the metabolite desmethylbromethalin in tissues.
  • Treatment: symptomatic with repeat dose activated charcoal and possibly lipid infusion.
  • Prognosis: guarded and may need prolonged aftercare.

Pathogenesis

Etiology

  • Direct ingestion of bait/pellets.
  • Relay or secondary toxicosis (eating small vermin which have been poisoned) may occur in the cat.

Predisposing factors

  • Cats are more sensitive to bromethalin than dogs.
  • Young age.

Pathophysiology

  • Both bromethalin and the active metabolite desmethylbromethalin uncouple oxidative phosphorylation.
  • There is inadequate ATP production by mitochondria and then decreased sodium/potassium ion channel pump activity.
  • Cells lose their osmotic control and retain sodium and swell with water resulting in cerebral edema and increased CSF pressure.
  • Cats are more sensitive to bromethalin than dogs and the oral LD50 in cats is reported to be 0.54 mg/kg and 1.8 mg/kg.
  • In toxicity studies cats remained well after 0.15 and 0.3 mg/kg, but the lowest lethal dose was 0.45 mg/kg of bromethalin (4.5 g of a 0.01% bait/kg).
  • In cases reported to the American Animal Poison Control Center deaths in cats have occurred from doses as low as 0.24 mg/kg.

Timecourse

  • Signs usually within 10 to 24 hours but not appear for 2 to 4 days, and progress slowly over anything up to 2 weeks.

Epidemiology

  • Cases are generally reported in North America and following changes in rodenticide regulations cases in companion animals are increasing.

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.
  • Kent M, Glass E N (2017) Bromethalin intoxication in cats. JAVMA 250 (10), 1089-1090 ResearchGate.
  • Tourdot R (2017) The decontamination dilemma: bromethalin ingestion. Today’s Vet Practitioner (1), 95-100 VetMedResource.
  • Rubinstein I, Weinberg G (2014) Antidote for bromethalin poisoning. Can Vet J 55 (1), 1185 PubMed.
  • Peterson M E (2013) Bromethalin. Top Companion Anim Med 28 (1), 21-23 PubMed.
  • Martin T, Johnson B (1989) A suspected case of bromethalin toxicity in a domestic cat. Vet Hum Toxicol 31 (3), 239-240 PubMed.

Other sources of information

  • Dorman D C (2006) Bromethalin. In: Small Animal Toxicology, 2nd edition. Peterson M E, Talcott P A (eds). St Louis, Missouri: Saunders Elsevier.

Organisation(s)


ADDED