Feral horse populations exist on every inhabited continent, managed through a combination of contraception, removal and culling programmes. The welfare of these animals is contested terrain between conservationists, ranchers and animal advocates.
Wild horse management involves genuine welfare trade-offs with no perfect solution. Large populations without management lead to starvation and habitat degradation; aggressive rounding and removal programmes cause acute welfare harm. Immunocontraception using PZP vaccine delivered by dart is increasingly recognised as the most welfare-positive management tool, avoiding both the suffering of mass removal and the slow suffering of overpopulation. Wild horse advocates and land managers increasingly agree that fertility control is the most pragmatic long-term strategy, but implementation at scale requires sustained funding.