The Case Against Ovariectomy

Warm Springs mares and foals in the corrals, Burns, OR

Warm Springs mares and foals in the corrals, Burns, OR


Sadly, the BLM is once again attempting to move forward with its hideous ovariectomy experiments on the mares from the Warm Springs, Oregon HMA. As many of you know, this procedure comes with high risk of complications, injury, and illness, sometimes resulting in death.  

 The process is pretty gruesome. A wild mare is driven into a squeeze-chute, located in a dusty, non-sterile barn. The veterinarian enters the vagina and makes an incision in the vaginal wall. He then enters the abdominal cavity with a tool called a “chain ecraseur”, a device that crushes, cuts and removes the ovaries. 

Filthy ovariectomy stall, Burns, OR

Filthy ovariectomy stall, Burns, OR

 We have gathered testimony from many reputable equine vets who caution strenuously against this procedure. It is inhumane and unfeasible for a number of reasons. The mares will suffer horribly if they are not provided proper sedation and local anesthesia, which is almost impossible to do with a wild animal. There are also often lethal complications with this procedure, including infection, excessive bleeding from the ovarian pedicles, and evisceration. 

 Though dangerous even for domestic mares, trained horses could be cross-tied after the procedure to prevent them from lying down, giving them a better chance to avoid the above-mentioned horrors. This is impossible to do with wild mares; however, and thus complications and death are more likely. 

 If a mare survives the procedure, her behavior will be changed. Her heat-cycle will have disappeared, will be irregular, or will be permanent. This will change herd-dynamics and could have untold consequences. A mare who is in permanent heat, for example, will be bred continuously by stallions, which could open up the incision, lead to infection, physical trauma, and again, death. 

 We argue that not only are these experiments incredibly inhumane, but that sterilizing herds is simply illegal. The 1971 Act that protects our Wild Horses and Burros clearly states that herds should be “healthy and self-sustainable”.  Sterilizing even a portion of a population will cause the genetic lines to narrow, and herds will quickly be subject to the negative health impacts of inbreeding. This will lead to local extirpation and eventual extinction. Is this what managing healthy, self-sustaining herds looks like? 

 We do not disagree that some large herds have been mismanaged for so long that the land cannot sustain the growing numbers. If the BLM had implemented the humane, reversible fertility control methods that have been available for years, they would not have reached these crisis levels. And, let’s not forget that it’s not only horses that use these lands; the range has been over grazed by livestock for decades. However, inhumane, expensive and non-reversible tools like sterilization are not the answer. It is time for the BLM to shift their focus and acknowledge the humane solution that exists. 

BLM gave us only a very short window to comment on this plan (deadline June 12th), likely because they know public opposition will be high. You can be sure we will be watching the situation closely, and will keep you informed of next steps. We have not given up the fight to save these mares from this horrible procedure. TCF has filed lawsuits twice in the past to stop these experiments and won! We can do it again, with your help.

Thank you so much for your dedication, support, and efforts; our majestic wild horses and burros need your voice and I know we can count on you to fight for them.

All the best, 

Elke Tukker

B.A. Candidate and Intern

The Cloud Foundation

Dana Zarrello