• This is a rodenticide affecting the central nervous system (CNS).
• Generally sold as a 0.01% bait.
• Bromethalin and its metabolite demethylbromethalin uncouple oxidative phosphorylation in the CNS which leads to loss of the Na+-K+ ATPase pump and retention of fluid in the brain and spinal cord, particularly within the myelin sheaths -> elevated CSF pressure.
• The toxic dose is not available for ferrets, but the median lethal dose varies by species; this falls between 0.25 mg/kg for pigs and up to 5.6 mg/kg for dogs.
• Bromethalin undergoes enterohepatic recirculation.
• Cause: ingestion of bromethalin bait.
• Signs: hindlimb weakness, paresis, paralysis.
• Diagnosis: history and clinical signs.
• Treatment: none once signs have begun, supportive and symptomatic, including steroids. Emesis, gastric lavage, activated charcoal.
• Prognosis: poor to grave.

Presenting signs

• Hindlimb weakness.
• Progressing to paresis and paralysis.