Bromadiolone

Bromadiolone is a potent anticoagulant rodenticide in the 4-hydroxycoumarin family, classified as a second-generation or superwarfarin agent. It is used in bait formulations to control rats and mice in domestic, agricultural, and industrial settings.

Mechanism and use: Bromadiolone inhibits the vitamin K epoxide reductase complex, blocking the recycling of vitamin K and depleting vitamin K–dependent clotting factors II, VII, IX, and X. This disruption impairs blood coagulation, leading to excessive bleeding if arodent or other animal ingests the compound. Its high potency and prolonged action make it effective at low doses and sustain its effect over time.

Toxicology and exposure: Bromadiolone is highly toxic to warm-blooded animals, including non-target wildlife and pets, if ingested. Because of delayed onset, signs of poisoning may appear days after exposure and include lethargy, pallor, bruising, nasal or gum bleeding, blood in urine or stool, coughing up blood, and other signs of internal bleeding. The risk is greater with repeated exposure or ingestion of multiple bait pieces.

Diagnosis and treatment: Suspected exposure requires veterinary or medical assessment. Diagnosis may rely on exposure history, clinical signs, coagulation tests such as prothrombin time or INR, and, when available, chemical detection. Treatment focuses on decontamination where appropriate and administration of vitamin K1 (phytonadione) for an extended period, with ongoing monitoring of coagulation status until normalization.

Environmental and regulatory notes: The long tissue persistence of bromadiolone raises concerns for non-target species, including birds of prey. Consequently, regulatory controls and strict adherence to label directions are common to minimize risks to wildlife, pets, and humans.