How does bromadiolone work against rats? - briefly
Bromadiolone is a second‑generation anticoagulant that blocks vitamin K epoxide reductase, halting blood clotting and leading to internal hemorrhage after repeated ingestion. Its hepatic accumulation allows a sub‑lethal dose to become lethal as the rodent continues to feed on the bait.
How does bromadiolone work against rats? - in detail
Bromadiolone belongs to the class of second‑generation anticoagulant rodenticides. After ingestion the compound is rapidly absorbed from the gastrointestinal tract and distributed through the bloodstream to the liver, where it exerts its toxic effect.
The toxic mechanism proceeds as follows:
- Inhibition of vitamin K epoxide reductase (VKOR) prevents regeneration of reduced vitamin K.
- Absence of reduced vitamin K blocks γ‑carboxylation of clotting factors II, VII, IX and X.
- Deficient clotting factors impair the coagulation cascade, producing internal bleeding.
- Hemorrhage develops gradually; clinical signs appear 2–5 days after the first dose, allowing the rodent to consume additional bait and increase the lethal dose.
Bromadiolone’s high lipid solubility enables accumulation in hepatic tissue, extending its half‑life and enhancing potency against resistant populations. A single dose of 0.1 mg kg⁻¹ body weight is sufficient to cause mortality in most adult rats, while sub‑lethal exposure may lead to chronic coagulopathy.
Safety considerations include:
- Minimal acute toxicity to non‑target mammals when used according to label directions.
- Potential secondary poisoning through scavenger consumption of poisoned carcasses; risk mitigated by bait placement and removal of dead rodents.
- Environmental persistence limited by biodegradation in soil and microbial activity.
The delayed‑action profile, combined with potent VKOR inhibition and hepatic storage, makes bromadiolone an effective tool for controlling rat infestations when applied with proper management practices.