U.S. Lab Animal Use Decline in 2024 U.S. laboratory animal use declined in the USDA-reported subset in 2024, with 776 facilities reporting 851,898 animals overall; excluding birds for year-to-year comparability, the total was 763,026, down from 844,915 in 2023, a nearly 10% decrease. The decline was broad-based, with fewer guinea pigs, dogs, cats, rabbits, nonhuman primates, hamsters, pigs, and sheep, while the only reported increase was in the “Other animals” category.
The reporting still covers only part of U.S. animal research because purpose-bred mice, rats, fish, and some birds remain outside USDA reporting requirements, leaving a substantial gap in visibility. NAVS also reported 56,601 animals subjected to painful or distressing experiments without pain relief in the 2024 USDA dataset, underscoring continued welfare concerns despite the overall decline.
Policy momentum toward non-animal methods has accelerated. FDA announced a plan in April 2025 to phase out animal testing requirements for monoclonal antibodies and other drugs using AI, cell-based systems, and organoids, and in April 2026 said it had reached Year 1 goals that included draft guidance reducing or eliminating nonhuman primate testing in monoclonal antibody development. EPA also recommitted in January 2026 to eliminating mammal testing by 2035 and has taken additional steps in 2026 to replace animal use with non-animal methods for chemical and pesticide safety assessments.
