FOIA Records: BLM Moved Forward with IUD Use without Scientific Accreditation

By Brieanah Schwartz

(March 15, 2021) The Bureau of Land Management (BLM) began the implementation of Intrauterine Devices (IUDs) in wild mares even though they remain unproven as an effective and humane population management tool. The first herd to receive IUDs is the Swasey Herd Management Area (HMA) in Utah. This precedent-setting move by the agency to implement IUDs without first studying and analyzing their effects and effectiveness is irresponsible wild horse management. 

The National Academy of Sciences (NAS) in its report on the BLM’s Wild Horse and Burro Program, stated that “IUDs may provoke undue uterine inflammation warrants caution and would require further testing before application in the field could be considered. In addition, evidence concerning loss rates of IUDs, especially during copulation, would be needed.” Using Science to Improve the BLM Wild Horse and Burro Program: A Way Forward (June 2013) at 130.

In response to these concerns, AWHC requested, in a letter dated July 2020, that the BLM delay implementation of IUDs until the agency can adequately study, quantify, and address the potential impacts this tool will have on wild horses through a formal research study and protocol executed in conjunction with a reputable scientific institution. 

When we received no response to our letter, we filed a Freedom of Information Act (FOIA) request for more information about the implementation of IUDs in the Swasey HMA. We recently received responsive documents to this request and immediately published this blog to do what the BLM has not, release to the public information about the implementation of IUDs in 8 wild, free-roaming horses from the Swasey HMA. 

Mare 05735374

  • 16 years old
  • 14.2 hh

Mare 10735402:

  • 11 years old
  • 14 hh

Mare 11735398:

  • 10 years old
  • 14 hh

Mare 12735426:

  • 9 years old
  • 14.1 hh

Mare 13735371:

  • 8 years old
  • 14.2 hh

Mare 13735383:

  • 8 years old
  • 14 hh

Mare 13735391:

  • 8 years old
  • 15 hh

Mare 14735393:

  • 7 years old
  • 14.2 hh

Another two mares received IUDs but when the BLM performed an ultrasound before their release, the IUDs had fallen out. 

The records showed that the BLM utilized a Y-Shaped Silicone IUD and revealed that the BLM worked with Oklahoma State University, even borrowing an IUD mold for a lot the agency commissioned itself. The BLM also took steps to work with the EPA in registering the device. When it came time to actually implement the devices, the BLM relied on their existing contract veterinarians and on the U.S. Geological Survey (USGS) to monitor the radio-collared animals every month for about two years and provide BLM with quarterly updates on animal health, foaling status, and movements. In short, at no point did the agency establish an affiliation with an academic institution to gain approval from an Institutional Animal Care and Use Committee (IACUC) on a scientifically sound and approved research protocol for the use of IUDs in the wild, free-roaming mares.

Frankly, the current rollout of unproven fertility control methods across the West involves experimenting on America’s wild horses without any scientific oversight or review, or, for that matter, any scientific method for determining the impacts of the experiments on the horses themselves. As such, AWHC continues to believe that the use of IUDs in this unscientific, unregimented proposal will jeopardize the horses’ long-term well-being and their natural, social behaviors, which are attributes that make wild horses celebrated American icons, treasured by Americans and others around the world. Thus, we will continue to monitor this operation closely.

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