California considers loosening restrictions on toxic rat poisons despite wildlife deaths

California’s Newsom administration is proposing to relax regulations on highly toxic rat poisons, a move that comes despite mounting evidence that these chemicals are killing wildlife throughout the state, including endangered species.

The controversial anticoagulant rodenticides work by thinning blood and preventing clotting, causing animals to bleed to death internally. While designed to control rat populations, these poisons create a deadly chain reaction as they move through the food web. Wildlife that consume poisoned rodents—from hawks and owls to mountain lions and foxes—often suffer the same fatal effects, with a new state report documenting widespread unintentional poisoning across California’s ecosystems.

The timing of the proposed regulatory rollback is particularly striking given California’s recent history with these chemicals. Just last year, after a decade-long legislative battle, the state passed landmark restrictions on anticoagulant rodenticides. The 2024 law required the California Department of Pesticide Regulation to maintain tight controls on these substances until scientific data could prove that affected wildlife populations had recovered to healthy levels.

The proposed changes represent a significant policy reversal that has alarmed environmental advocates and wildlife biologists. Critics argue that loosening restrictions now—before comprehensive recovery data is available—could undo years of conservation progress and further threaten California’s already vulnerable wildlife populations. The debate highlights the ongoing tension between pest control needs and wildlife protection in the nation’s most populous state.