The Bureau of Land Management (BLM) has abandoned a plan to surgically sterilize wild mares, according to some wild horse advocates. Meanwhile, a National Wild Horse and Burro Advisory Board resolution could put animals already in holding facilities in danger, some advocates say.

The Wild Free-Roaming Horse and Burro Act of 1971 protects wild horses and places them under BLM jurisdiction. The agency estimates that 67,000 wild horses currently reside on public lands in 10 Western states. Another 45,000 animals reside in short- and long-term holding corrals, agency statistics say.

In June, the BLM announced that, in cooperation with Oregon State University, it would “develop and evaluate safe and humane methods to spay” wild horse mares as a way to manage herd growth. The proposed surgeries would be performed on 100 mares residing in corrals in Hines, Oregon.

In response 35 wild horse advocacy groups went on record to oppose the research project on grounds that the surgeries would be performed in a nonsterile environment and could result in potentially fatal complications, including hemorrhage, infection, and colic