“Preliminary Results with GonaCon Immunocontraceptive Vaccine in Wild Horses at Theodore Roosevelt National Park Shows Promising Results” 

This statement was released May 14, 2015 by Dr. Dan Baker, of Colorado State University, to North Dakota Badlands Horse (NDBH), a 501 (c) (3) nonprofit which advocates for and promotes the free roaming horses of Theodore Roosevelt National Park (TRNP).  NDBH has a Partnership Agreement with TRNP to assist in low stress captures and placement to pre-approved homes of those removed 

horses.  

Dr. Baker added the following:

“Researchers from Colorado State University, in collaboration with resource managers at Theodore Roosevelt National Park (TRNP), North Dakota began a research investigation in 2009 to evaluate the effects of an immunocontraceptive vaccine, known as GonaCon, on reproduction and side-effects in free-ranging horses. Initial results indicated that while the vaccine was safe for pregnant females and developing fetus and had no adverse effects on social behaviors, it was only about 50% effective in reducing foaling rates over a two – year period. This is not nearly effective enough to manage the growth rate of most populations of free-ranging wild horses.

In an attempt to improve the effectiveness of this contraceptive, researchers re-immunized previously vaccinated mares at a scheduled roundup at TR in 2013. Results of preliminary foaling rates of treated mares in 2015 are remarkable and encouraging. To date (edited to read-September 1 2015), not a single mare that was re-vaccinated with GonaCon in 2013 has delivered a foal this season whereas almost 70% (17/25) of untreated mares have already done so. It’s still too early to confirm infertility in these mares but if these results persist for the duration of this breeding season and beyond, researchers will need to address the question of how long does GonaCon suppress fertility in TR horses and are there any long-term side-effects of this vaccine treatment. Unfortunately, long-term funding for this research has not been forthcoming and researchers are seeking financial support from government agencies and private foundations to continue this important and promising effort.”    Dan L. Baker, PhD, Affiliate Faculty, Department of Biomedical Sciences, Animal Reproduction and Biotechnology Laboratory, Colorado State University

Blake McCann, Wildlife Biologist, Theodore Roosevelt National Park stated that “these preliminary results are very promising.  It is hoped that this research will continue to be funded so that all aspects of GonaCon as a potential horse population management tool may be understood. The park will issue a news release on the study at the conclusion of the 2015 foaling season, when definitive results have been obtained.” 

Three NDBH Board of Directors have been Field Technicians with this project.  NDBH is honored to be a part of this groundbreaking research.  
Funding has been found to continue this important research in the coming years.  It is imperative that those who are responsible for wild horse herds throughout the country and the world, have more effective and safer tools to use in keeping populations manageable.

Marylu Weber, NDBH President