Horse Advocates Seek Injunction to Block Trump Administration from Surgically Removing Ovaries of Wild Mares

Photo by Christine Mendoza
Photo by Christine Mendoza

Portland, OR—A coalition of animal protection and wild horse advocacy groups filed a motion Friday for a preliminary injunction in US District Court in Oregon to stop the Bureau of Land Management (BLM) from performing risky and inhumane sterilization surgeries on wild mares in Oregon. The procedure involves blindly locating and severing the ovaries while the animals remain conscious.

The preliminary injunction motion was filed by the public interest law firm Meyer, Glitzenstein and Eubanks LLP on behalf of the Animal Welfare Institute (AWI); The Cloud Foundation (TCF) and its executive director Ginger Kathrens, who is also the Humane Advocate on the BLM’s National Wild Horse and Burro Advisory Board; the American Wild Horse Campaign (AWHC); and wildlife photographer Carol Walker, who is also a director of field documentation for the Wild Horse Freedom Federation.

At issue is the BLM’s decision to proceed with surgical sterilization experiments on 100 wild mares from the Warm Springs Herd Management Area in Oregon, despite significant public outcry, veterinary opposition, and the withdrawal of Colorado State University, which was previously slated to partner with the BLM and oversee the experiments. After CSU withdrew in August, the BLM announced two weeks later that it would nevertheless proceed with the plan and simply dropped the objective of determining whether the experiments were humane.

The BLM now intends to begin performing the highly invasive and risky surgery—known as “ovariectomy via colpotomy”—on the mares at the agency’s Hines, OR, facility beginning on November 5.

“Ovariectomy via colpotomy” is widely regarded to be an outdated and inhumane surgical procedure. The National Academy of Sciences explicitly called this procedure “inadvisable” due to health risks in its comprehensive report on wild horse management. Under this method of sterilization, a veterinarian inserts his arm into a mares’ abdominal cavity through an incision in the vaginal wall, manually locates the ovaries, then twists, severs and removes them using a rod-like tool with a chain on the end. The BLM’s experiment involves performing ovariectomies on pregnant mares—which carries significant risks to both the horses and the unborn foals—in an effort to quantify the incidence of abortions that would result.

“Because the BLM is choosing to experiment on America’s wild horse mares by ripping out their ovaries with a chain, killing any unborn foals, public observation is absolutely essential,” Kathrens of The Cloud Foundation said. “It is appalling to consider the use of this medieval, gruesome procedure in the unsterile environment of the Hines Corrals, let alone out on the range.”

AWI and the other plaintiffs initially filed their complaint on Sept. 21 against the BLM, citing violations of the US Constitution and three federal laws.

As part of the lawsuit, equine veterinarians submitted sworn declarations detailing numerous animal welfare concerns with the BLM’s plan. One veterinarian with extensive experience operating on wild horses emphasized that this procedure “is extremely risky due to its blind nature” and that it is “inherently difficult for a surgeon to avoid severing other organs, including the bowel, and causing severe infection and internal bleeding during this blind approach.”

Further complicating matters is the BLM’s refusal to allow meaningful observation by independent observers. The lawsuit argues that this refusal violates the plaintiffs’ rights under the First Amendment to observe and document these experiments—a critical component of the public’s ability to understand how the BLM is attempting to manage federally protected wild horses.

“The BLM’s aggressive pursuit of dangerous sterilization surgeries flies in the face of the statutory mandate the agency must abide by to protect America’s wild horses,” said Joanna Grossman, Ph.D., AWI’s equine program manager. “That the BLM is blocking these ovariectomy experiments from public view is not at all surprising. The public would be aghast to learn the full details of these highly invasive surgeries that endanger the welfare and lives of these animals.”

“The BLM must abandon its plan to perform this barbaric surgical experiment on federally protected wild horses,” said Brieanah Schwartz, government relations and policy counsel for the AWHC. “The inhumane nature of this procedure has been documented on video, demonstrating why the BLM is dead set against providing meaningful public observation of the experiments. Once the public sees what our government is doing to our cherished wild horses, the American people won’t stand for it.”

Media Contact Information

Margie Fishman, (202) 446-2128, [email protected]

The Animal Welfare Institute (AWI) is a nonprofit charitable organization founded in 1951 and dedicated to reducing animal suffering caused by people. AWI engages policymakers, scientists, industry, and the public to achieve better treatment of animals everywhere — in the laboratory, on the farm, in commerce, at home, and in the wild. For more information, visit

The American Wild Horse Campaign (AWHC) is a national wild horse advocacy organization whose grassroots mission is endorsed by a coalition of more than 60 horse advocacy, public interest, and conservation organizations. AWHC is dedicated to preserving the American wild horse in viable, free-roaming herds for generations to come, as part of our national heritage.

The Cloud Foundation (TCF) is a Colorado 501(c)3 nonprofit corporation, that grew out of Executive Director Ginger Kathrens' knowledge and fear for wild horses in the West. TCF works to educate the public about the natural free-roaming behavior and social structure of wild horses and the threats to wild horse and burro society, to encourage the public to speak out for their protection on their home ranges, and to support only humane management measures. Kathrens serves as the Humane Advisor on BLM’s National Wild Horse and Burro Advisory Board.