The EPA’s official registration of the first contraceptive vaccine for horses means it can now be used to support sustainable wild horse populations in the West. The vaccine, ZonaStat-H, more commonly referred to as porcine zona pellucida or PZP, has been used on Assateague wild horses for more than 20 years. The registration of the vaccine was sponsored by the Humane Society of the United States, which believes it could be a historic step in efforts to protect remaining free-roaming wild horses and burros in America.
Human Society President and chief executive Wayne Pacelle wrote in his blog, A Humane Nation:
“The federal management program for wild horses has been something of a financial and animal welfare disaster for quite some time. In recent years, the BLM has rounded up tens of thousands of horses, causing distress and fear and some occasional deaths, without any reasonable expectation to adopt out these animals. That has resulted in a swelling captive population of wild horses―now more than 45,000. Almost half of the agency’s entire budget goes toward captive horse management.
If there is pressure or reason to reduce the population, then the primary management tool from this point forward should be fertility control, rather than costly and sometimes dangerous round-up and removal regimes. PZP is now ready to be used for this purpose. The contraceptive vaccine prevents female horses from becoming pregnant, and it is safe for the animals and the environment. Above all, it can be used to maintain sustainable populations, since the American public wants wild horses roaming the West. By using more fertility control to humanely reduce wild horse populations on the range, and having fewer horses in long-term federal holding pens on the government dole, U.S. taxpayers can save tens of millions over the next decade.”