Brodifacoum is a highly lethal 4-hydroxycoumarin vitamin K antagonist anticoagulant poison. In recent years, it has become one of the world’s most widely used pesticides. It is typically used as a rodenticide but is also used to control larger pests such as possum.

Brodifacoum has an especially long half-life in the body, which ranges to several months, requiring prolonged treatment with antidotal vitamin K for both human and pet poisonings.

Rats (oral) 0.27 mg/kg
Mice (oral) 0.40 mg/kg
Rabbits (oral) 0.30 mg/kg
Guinea-pigs (oral) 0.28 mg/kg
Squirrels (oral) 0.13 mg/kg
Cats (oral) 0.25 mg/kg
Dogs (oral) 0.25 — 3.6 mg/kg
Birds 1 mg/kg — 20 mg/kg
Fish 0.04 mg/kg