Wild horses and burros on US public lands are managed through fertility control and roundup programs. The welfare implications of different management approaches vary enormously and remain highly contested.
Wild horse and burro management is a genuine welfare dilemma with no easy answers. Overpopulation on public lands causes range degradation, starvation, and resource competition — all welfare harms to the horses themselves. But the primary management tool — helicopter roundup — causes significant acute trauma. Fertility control using PZP provides an evidence-based, humane alternative that reduces population growth without the welfare costs of capture. The political and economic barriers to scaling PZP to the extent needed remain significant, but the welfare case for prioritizing non-lethal population management is strong.