bromethalin

Bromethalin is a synthetic neurotoxic rodenticide used in baits to control rat and mouse populations. It is formulated in pellets, blocks, or liquid/oil-based products and is intended to be placed in bait stations or areas where rodent activity is detected. Because of its high toxicity to mammals and birds, regulatory labels specify precautions to reduce exposure to non-target species.

The poison acts as a mitochondrial uncoupler, disrupting oxidative phosphorylation in brain cells and other tissues. This rapid depletion of adenosine triphosphate leads to energy failure, cerebral edema, and neurological dysfunction. Unlike some anticoagulant rodenticides, bromethalin does not affect blood clotting, and there is no widely available antidote.

Clinical signs typically appear 4 to 36 hours after ingestion, though delays of several days can occur. Early symptoms include tremors, hyperexcitability, and ataxia, which may progress to seizures, hindlimb weakness, paralysis, coma, and potentially death. The severity depends on the dose and the animal’s health. Non-target species and domestic pets are at risk if they ingest bait, and wildlife can be affected through environmental exposure.

Treatment is supportive and symptomatic, as there is no specific antidote. Decontamination may be considered if ingestion is recent. Veterinary care may include aggressive fluid therapy, anticonvulsants for seizures, and measures to manage brain edema (such as mannitol). The prognosis varies; rapid, intensive treatment improves outcomes, but high-dose exposures can be fatal.

Regulatory and safety notes emphasize proper storage, use of tamper-resistant bait stations, adherence to label directions, and keeping bait out of reach of children and pets.