Rodenticide Poisoning: Secondary Toxicity and Wildlife Welfare

Second-generation anticoagulant rodenticides are among the most pervasive wildlife poisons in use, killing owls, hawks, foxes, and other predators through secondary poisoning of rodent prey.

Key Facts

Second-generation anticoagulant rodenticides (SGARs) cause death by internal bleeding over several days
Residues are found in over 90% of tested barn owls, red kites, and buzzards in the UK
Secondary poisoning occurs when predators eat rodents that have ingested rodenticide but not yet died
Rodenticides are legally used by professional pest controllers but also widely available to the public
Effective alternatives including trapping, exclusion, and first-generation rodenticides pose lower secondary toxicity risk

Welfare Considerations

Anticoagulant rodenticide poisoning causes prolonged, painful deaths in both target rodents and non-target predators. The welfare cost falls across multiple trophic levels. The conservation and welfare case against SGARs is strong, and some countries have restricted public access while maintaining professional use. Even where legal, the precautionary principle supports preferring alternatives where rodent control is needed indoors. Urban and agricultural use near natural habitats poses the greatest non-target risk.

What You Can Do

Never use second-generation anticoagulant rodenticides in your home or garden
If rodent control is needed outdoors, contact a professional pest controller and specify no SGARs
Report suspected poisoned wildlife to your local wildlife trust or raptor protection group
Advocate for tighter restrictions on public sale of second-generation anticoagulant rodenticides