Friends of Animals tries to stop use of PZP
WASHINGTON D.C.––Friends of Animals on May 20, 2015 asked the U.S. Environmental Protection Agency to “consider new scientific evidence demonstrating the need to cancel the registration of porcine zona pellucida (PZP) for population control of America’s wild horses and burros, which was issued to the Humane Society of the United States in 2012,” the FoA cover letter to EPA chief administrator Gina McCarthy said.
HSUS won registration of a PZP-based immunosterilant called ZonaStat-H, developed for use in controlling wild horse and burro populations, in January 2012, after a three-year application process.
Summarized FoA Wildlife Law Program legal director Michael Harris, “HSUS requested waivers for most of the studies ordinarily required from an applicant seeking a pesticide registration, including a toxicity study, ecological effects and environmental fate guideline study, and an efficacy study. The requested waivers were granted.
HSUS “was allowed to seek its registration based on several studies conducted in the 1990s.” Harris continued, “regarding the efficacy of the drug as a wild horse and burro contraceptive. These studies conclude overall that PZP can be highly effective at reducing fertility rates among wild horses with little to no side effect. A majority of these reviews were published by Jay Kirkpatrick, a veterinarian who manufactures PZP for use on wild horses.”
Responded Kirkpatrick by e-mail on May 29, 2015, “I am not a DVM. That might help explain how much FOA understands.”
Claims side-effects were not considered
HSUS and Kirkpatrick, Harris charged, “did not consider the biological, social and behavioral effects the drug can have on wild horses.”
Since ZonaStat-H won EPA approval, Harris said, “PZP has been in widespread use. For example, the Bureau of Land Management, which has jurisdiction over the largest number of wild horse herds on federal public lands, has administered approximately 1,944 doses of PZP to wild mares. The U.S. Forest Service has used PZP on mares in the Carson National Forest and potentially elsewhere. The use of contraception generally, and the use of PZP specifically, is advocated by the U.S. Geological Survey and the National Academy of Science.”
Argued Harris on behalf of FoA, “Research has now demonstrated changes in mare stress and reproductive physiology, in addition to changes in male behavior,” allegedly resulting from use of PZP.
“For example,” Harris said, “researchers now know that PZP poses the risk of immediate physical damage to the dosed mares, can increase the mortality rate in foals born to treated mares after the PZP loses its effectiveness, can result in social disruptions among herds with treated mares that can damage long-term herd cohesion that is critical to the health of the animals, and places the wild horses at risk of a genetic bottleneck.
“Although the information regarding PZP used to support its registration is generally accurate regarding PZP efficacy,” Harris allowed, “with regards to ecological and environmental effects it is outdated now.”
Kirkpatrick fires back
Challenged ZonaStat-H developer Kirkpatrick in a May 18, 2015 op-ed response published by the Salt Lake Tribune, “Identify wild horse populations where PZP has disrupted the social structure or social behaviors of the horses. Explain why this hasn’t even happened in the Cape Lookout, North Carolina population where this theory originated.
“Identify any wild horse population where PZP has disrupted social organization or social stability to the point of decreasing reproductive success,” Kirkpatrick continued. “Explain why this hasn’t happened at Cape Lookout.
“Identify any wild horse populations where PZP has increased the length of the foaling season and resulted in decreased foal survival. Include Cape Lookout in this answer.
“Identify any wild horse population where PZP treatment has resulted in a decrease in body condition scores, or an increase in adult or foal mortality, or a decrease in longevity. Conversely,” Kirkpatrick finished, “identify any wild horse populations where PZP treatment has increased body condition scores, decreased mortality and increased longevity.”
Assessed American Wild Horse Preservation Campaign director Suzanne Roy, “This petition to the EPA to cancel the registration for PZP is a frivolous action that lacks any scientific basis and ignores decades of research on the safety, efficacy and impacts of PZP fertility control on a variety of wildlife species, including wild horses. Even Cassandra Nunez,” author of three scientific papers cited in the FoA petition, “concluded in a 2010 paper, “When the alternative (gather and removal) is considered, PZP is currently managers’ most humane and effective option for population control.’”
“The American Wild Horse Preservation Campaign — made up of more than 60 groups, including HSUS, the Animal Welfare Institute and In Defense of Animals—has been willing to accept treating mares with the anti-fertility drug PZP as a more humane alternative to gathering and shipping mustangs to costly holding facilities,” summarized Scott Sonner of Associated Press in an April 2015 review of the conflicts leading up to the FoA filing.
By contrast, Sonner continued, FoA and Protect Mustangs, of San Francisco, “say recent studies show use of the contraceptive, which keeps the horses from reproducing for two years, is having an unnatural impact on the herds’ social structure. U.S. District Judge Larry Hicks in Reno agreed in February 2015 when he blocked a roundup based partly on BLM’s reliance on a 5-year-old study that largely ignores newer data suggesting contraception prompts some mares [who have been] unable to become pregnant to leave [their original bands] in search of stallions in other bands.”
Follow the money
HSUS, Sonner noted, “has the patent on PZP, and [FoA president Priscilla] Feral and others argue they benefit financially from its use.”
Countered Kirkpatrick in the Salt Lake Tribune, “If this is true, where is the patent number? PZP is actually produced on a non-profit basis. If there were a profit to be made, why aren’t for-profit companies making the vaccine, which is not patented?”
HSUS senior vice president Holly Hazard, who more than 25 years ago worked for Feral at FoA, before heading the Doris Day Animal League, which in 2005 merged into HSUS, “We have been working with PZP for 20 years. We believe it’s the best hope for getting the wild horse management challenges under control.”
Hazard told Sonner that the conflicting animal advocacy organizations share the same “pure vision of what we’d like to see—which would be horses remaining on the range, untouched by man. But if the only argument you can make is they should be left free on the range,” Hazard qualified, “I say that they are not now and will not ever be—at least in the reasonable future. We want a solution. We don’t want to rattle our saber toward a victory that will never come.”
Sex, drugs, & FoA
While HSUS allegedly has an apparent pecuniary interest in promoting PZP, FoA has a long history of opposing the use of animal contraceptives. FoA opposition to animal experiments done to develop Neutersol [now sold as Esterisol] in 1991 influenced HSUS to withdraw temporarily from funding some of the work. The HSUS subsidiary Humane Society International later was involved in field-testing Neutersol in several other nations.
Founded in 1957 to promote low-cost dog and cat sterilization surgery, FoA continues to raise about 40% of its annual income through the sale of vouchers for discounted dog and cat spay/neuter operations. Providing spay/neuter services also occupies about 40% of the FoA program budget.
FoA president Feral has explained at least twice, in 1991 and 2008, that while FoA has not endorsed any non-surgical sterilization methods, FoA might endorse a non-surgical sterilization method if it causes less trauma to the animals than surgery, and is otherwise safe, effective, and affordable.
Feral mentioned that her considerations in deciding whether to endorse a non-surgical sterilization method would include how the method is developed and whether animals are killed to produce it. A product using stem cells extracted from tissues removed during conventional sterilization surgery would be more acceptable to FoA, Feral said, than a product using the remains of animals slaughtered for food.
Against wild horse herd reduction
But FoA does not favor any approach to wild horse herd reduction. In June 2014 FoA and the Colorado-based Cloud Foundation asked Interior Secretary Sally Jewell to protect wild horses under the Endangered Species Act, “since the Wild Free-Roaming Horse & Burro Act, which was passed in 1971, has failed to protect our wild horses,” said an FoA media release.
“Six states have already lost their wild horse populations—Missouri, Iowa, Arkansas, Texas, Oklahoma, and Kansas,” the release added.
Said FoA Wildlife Law Program attorney Jenni Barnes, ““Now there are less than 35,000 [wild horses] on public lands, where they are supposed to be protected,” Barnes said. “Our petition states that these few remaining horses are divided into even smaller herds [by government management policies], whose populations are so low that they are susceptible to being wiped out completely by a chance event or change in the environment. Instead of protecting these horses, or just leaving them alone, a government agency, the Bureau of Land Management, plans to remove even more horses from the range with expensive and cruel tactics, such as helicopter driving. Once the government labels wild horses as ‘excess,’ the Wild Free-Roaming Horse & Burro Act does not protect them.”
Jewell has yet to respond to the FoA and the Cloud Foundation, who reportedly are preparing to file a lawsuit to force a response.
“Wild Horse Annie”
The FoA and Cloud Foundation arguments have been endorsed by the International Society for the Protection of Mustangs & Burros, the oldest wild equine advocacy organization, which points out that “Wild horse and burro populations have been nearly cut in half since 1971 when Congress declared they were ‘fast disappearing from the American scene’ and responded by adopting the Wild Free-Roaming Horse & Burro Act. ISPMB was founded by Velma “Wild Horse Annie” Johnston (1912-1977), who began advocating for wild horses in 1950 and enjoyed her first legislative success in 1952.
The development of ZonaStat-H, the PZP-based contraceptive challenged by FoA, was partially funded by the American SPCA, as well as HSUS. The active component of ZonaStat-H is based on porcine zona pellucida, extracted from the ovaries of slaughtered pigs.
The potential contraceptive use of PZP was discovered at the University of Tennessee in 1972. The Science & Conservation Center at ZooMontana, founded by Jay Kirkpatrick, DVM, has produced and tested PZP-based contraceptive vaccines since 1998.
A rival product, GonaCon, developed by USDA Wildlife Services, is a vaccine based on antibodies to the hormonal triggers that produce the sex hormones estrogen, progesterone and testosterone. Tested on wild horses in the Pryor Mountains and Theodore Roosevelt National Park, North Dakota, and on urban deer in New Jersey and Maryland, GonaCon also shows promise as a contraceptive for dogs and cats.
ANIMALS 24-7 found considerable disagreement among wild horse advocates and contraceptive researchers about the use and side effects of PZP. For political reasons, however, most were unwilling to comment on the record.
An exception was Willis Lamm, a former California firefighter who retired to focus on wild horse advocacy in 1998.
“I have observed fertility-controlled herds in the Virginia Range of Nevada for many years,” Lamm told ANIMALS 24-7. “Several of us, as volunteers, kept photographic records of bands of horses in which some members had received PZP and others received other fertility control methods. Going in, we had no knowledge as to which horses had been given which form of fertility control. The mares that we determined later were provided PZP showed no ill effects. In fact, the only observable side effects were short intervals in which they did not produce foals and developed improved body scores while they rested from gestating and nursing.
“We did not observe the entire life cycles of the Virginia Range horses,” Lamm acknowledged. “However, reports from organizations that monitored Barrier Island horses on the Atlantic Coast over multiple decades indicated that the treated mares, on average, lived several years longer than untreated mares.
“We observed some behavioral issues with horses that had received contraceptives other than PZP that may have been associated with those products,” Lamm said. “The social structures of the PZP treated horses were more influenced by human interference––tourists and meddlers––than by any side effect that we could attribute to the vaccine. The horses who kept to remote areas stayed socially integrated, while the behaviors of horses, treated or not, tended to be disrupted where humans regularly imposed themselves on the bands.
How PZP works
“I also took the time to learn how PZP works, what it does and what it cannot do,” Lamm continued. “PZP is a vaccine that, simply put, produces an antibody that affects the zona pellucida (outer lining) of a mare’s egg and prevents sperm from successfully penetrating. While individuals of any species can have varying degrees of sensitivity to any vaccine, the probable deviation associated with PZP would involve the length of efficacy. Some mares produce antibodies for shorter time periods and others produce antibodies for longer time periods. Many claimed side effects of PZP appear to be impossible for the vaccine to produce.
“It seems medically possible that excessive repeated inoculations with PZP could generate antibody responses beyond the desired period, particularly in hypersensitive individuals,” Lamm allowed. “I would accept that this is an area that warrants further objective study.
“Nonetheless,” Lamm said, “keeping horse populations in balance with range resources is a range management necessity. Most of these herds are by law restricted to ranges having defined boundaries. While there is plenty of room to argue the relative value of various range management models and grazing resource priorities, the fact remains that populations eventually exceed the carrying capacity of these defined areas. Thus two practical choices are on the table––remove excess horses, or reduce the foal crops produced in these herds.
Removal vs. reduction
“Removing horses permanently excludes members from the gene pool,” Lamm pointed out. “Reducing the numbers of foals produced from each mare can help to limit herd growth without compromising the overall genetic diversity of the herd. Simply put, a larger and more genetically diverse number of mares will each contribute fewer new members into the herd in an effort to achieve balance.
“Given that the strength of free-roaming horses relies a great deal upon genetic diversity and natural selection,” Lamm concluded, “the most rational approach to herd management involves approaches that preserve the maximum possible genetic diversity.”
There is no overpopulation of wild horses. This is a myth perpetrated and fostered by special interests whose purpose is to plunder our public lands for private profits. The last population census was done in 1982 and although a taxpayer funded NAS study on wild equines was released 2 years ago, it contained no new population census nor did it address the range/riparian damage caused by 7-10 million welfare cattle & sheep on the wild horses/burros legal land. Biologists estimate the real number left in the wild to be 15-18,000 across 10 states on nearly 29 million acres of legal domain. Over 70% of remaining herds are below genetic viability. The burros are a critically endangered species according to the UCN Species Survival Commission.
The burden of proving an overpopulation exists should rest on the BLM. Appropriate Management Levels randomly assigned to different herd areas have no basis in science and do not support genetic viability; in fact they are another tool in the BLM extinction goals. I’ve seen AML as low as 66 individuals! That is NOT managing for preservation! These wild equines are native species, have a ecological niche to fill, are on their legal land, and have every right to natural selection reproduction and protection under the Law.
Merritt Clifton says
Several of the factual contentions here may be evaluated from varying perspectives. For example, “overpopulation” that results horses dying of starvation and drought, which occurs sometimes, is a worst-case scenario resulting from “overpopulation” at a lower level that causes the horses to try to disperse beyond BLM land, into private property and into government land set aside for other species (including endangered species) and other uses. The claim that “the last population census was done in 1982” rests on the contention that the censusing methods used since then are less accurate. In light of the many advances made since then in use of aerial surveys, GPS mapping, etc., this can certainly be disputed. Under the present drought conditions prevailing over much of the west, the combined population of cattle and sheep remaining on the range appears to be in the 3-4 million range — and regardless of the numbers, reality is that the same legal framework allocating some BLM range land to wild horses and burros since 1971 had decades earlier given priority to cattle and sheep. The Wild Free-Roaming Horse & Burro Act of 1971 established some limited rights for wild horses to exist on BLM land, but it did not give the equines a higher priority than cattle and sheep. Finally, while an argument can be made that “These wild equines are native species, [and] have a ecological niche to fill,” and while ANIMALS 24-7 has in fact made and endorsed that argument, also to be recognized is that all of the largest, most influential wildlife conservation groups in the U.S. consider wild equines to be non-native, and are pushing at least as energetically as ranching interests for their extirpation. Bashing the BLM for executing policies originating from higher up in the Department of Interior is shooting at the wrong target.
Janet Schultz says
I steamrolled through your comment – but your last sentence caught my eye. What policies are being executed from higher up that BLM is not responsible for? Sounds like an evasive loophole and one we in America and all free thinking individuals in the world REJECT! You cannot have a government in this country that executes repulsive policies and evade accountability by pointing behind them.
So, I want to know, which policies are not the responsibility of BLM.
Merritt Clifton says
An elementary knowledge of civics would inform Janet Schultz and anyone else of similar views that the Bureau of Land Management is not a policy-making body at all. The BLM exists to execute the policies of the Department of Interior, which are in turn established by Acts of Congress and directed by the Secretary of Interior, who is appointed by the President of the United States. Congress, whether or not one likes what it does, is elected on a representational basis by the voters of the United States, who also elect the president.
Jamaka Petzak says
Though this is a complex issue and no drug is without side effects, I believe the government’s aim is to eradicate wild horse and burro populations; and perhaps, if they are intent upon destroying (“developing”) the last lands the horses have always lived on, sterilizing them permanently would be the kinder alternative. Also, it should be abundantly clear that the species that really needs contraception in a much bigger way than it now utilizes, is our own.
Mar Wargo says
PZP is not the future when there is enough doubt about its safety and what possible harm it is actually capable of. While the herds are now at below viable levels, the most promising action we can take would be for a 10 year renewable moratorium to take the time to recover the herds from inbreeding and to use the first-ever field research on the behavior of wild horses to create their own population boundaries. A moratorium would stop all the aggression and removals and reassert the law, if it has any teeth left, and use this time of low populations to protect the herds from further losses. In the end, these are wildlife and they must be accorded their freedom on their own, now considerably lessened lands.
Mary Finelli says
Anyone concerned for wild equines should, at the very least, not support the cattle or sheep industries.
Dustin Rhodes says
Karen Sussman says
After monitoring four wild herds, some as long as 16 years now, we note that what contributes to increased fertility rates is band destabilization through constant roundups by the BLM.
Our two herds that hadn’t been gathered upwards to 10- 50 years show very healthy behaviors and these herds grow at a very slow pace. We have not removed, gathered or disrobed the family band structures here for 14 years and we have noted that our horses do not double every four years like the BLM herds – as they say.
You will note in the NAS studies of 2013, using birth control was only one way of management. The study also noted that BLM’s management practices are facilitating high rates of population growth by holding horse populations below levels affected by food limits..
We have noted here that with the best of food availability, the horses still keep their population rates very low. We started out with 70 White Sands Wild Horses in 1999. After 16 years we are now just over 200 horses. If you use BLM’s stats multiply by 2 every four years and you will see how many horses BLM would have by 2015..
BLM has had such intrusive management of a highly social species, there is no doubt that from the lack of understanding wild horse./burro behaviors, that we could be seeing dysfunctional behaviors out there. For instance, on our two stable herds, fillies don’t foal until they are four and five years of age. Now we see on public lands 2 year olds in foal. We began to see the beginning of this during Fred Wyatt’s term at Palomino Valley. Something that he had not seen in the past.
The constant disruption of the family bands destroys this herd wisdom of the old stallions who cannot compete with young stallions once they are all turned back to the wild as they had done with selective removals since the early 90’s.
What needs to be done is to put a moratorium on rounds ups, evaluate the behaviors of the herds and make management decisions following the evaluations.
And finally, why is everyone missing the one recommendation of the NAS Committee which states to leave them alone?
In the meantime, if we truly are concerned about the habitat conditions of public lands, then we should be removing livestock in lieu of wild horses. But until everyone is ready to take a stand to protect habitat, then wild horses/burros will be the scapegoat.
Merritt Clifton says
With all due respect, a population increase from 70 to 200 in only 16 years represents a growth rate of more than 8% per year, more than four times higher than the global human population growth rate of 1.2% over the same time frame. That is not a “slow pace” of growth; that is an unsustainable growth rate for practically any species of large habitat needs and high longevity.
sandra longley says
as far as feral vs native-there were no europeans or settlers out west when the land was explored by lewis and clark, who saw vast herds of wild horses and indians mounted on them, a handful of trappers who gathered furs for the european trading companies in canada, texas was described as being covered by a million wild horses when settlers drifted into Mexican territories in america..there is no definitive case just theories that horses disappeared from the continent of the americas where the species actually originated..that would be like saying the buffalo were cattle turned loose by ranchers-ridiculous
Merritt Clifton says
Spanish explorers had already taken horses into California, Nevada, Utah, Colorado, New Mexico, and Texas more than 100 years before Lewis & Clark ventured west in 1804. Permanent settlements with mounted garrisons were established in Texas by 1690, and in the San Francisco Bay area by 1769. There was also extensive documentation of the geography, flora, fauna, and Native American cultures of the Pacific Northwest produced by British, French, and Russian explorers produced for more than a century before the Lewis & Clark expedition; none of them saw evidence of horses or use of horses. Neither is there fossil evidence of horses existing in North America for approximately 10,000 years before the Spanish arrival. There is, however, extensive fossil evidence that many other species which once coexisted with the ancestral horses in North America also died out during the Ice Ages, leaving direct descendants only in Asia and Africa.
Janet Schultz says
The evidence of fossils have been in extensive fields at Adobe Town and Salt Wells. As a matter if fact the fossils of horses from prehistoric times is art and parcel of the enticement to that area to tour. Imbedded fossils have been found in the Los Angeles area, prehistoric remains. Drawings of horses are found in the Red Desert of AZ. There are journals from the times of Marco Polo speaking to trading by the Chinese with the West Coast people for horses and on and on. There is no reason to think that with the natural grasslands and abundant water on this continent that horses of some sort did not exit it is just closed minded to consider that all species did not exist everywhere on a world that was abundantly providing for its inhabitants, including homo sapien who was able to live just about everywhere. Do you think that every other creature that is able to live just about everywhere, did not?
Merritt Clifton says
The fossils of early equids found at Adobe Town and Salt Wells date, respectively, to the late Eocene and to the Miocene epochs, more than 33 million and more than five million years ago, long before the Ice Age from approximately 23,000 to 13,000 years ago which coincided with the loss of horse ancestors and many other large animals from the North American fossil record. The remains of two horses and a burro excavated near Carlsbad, California in 2013 apparently lived and died at some point between 1625 and 1705, according to carbon dating, a time predating permanent Spanish settlements in California but well into the era of Spanish exploration of the region, which began in 1542. The Ming dynasty in China engaged in extensive and well-documented horse trading — with the Mongols and other Central Asian horse cultures. There is no record of any ancient Chinese horse trading by sea voyages of thousands of miles, nor of Native Americans along the West Coast having horses prior to European settlement. The peak of Ming dynasty Chinese maritime culture, coinciding with the life and seven major voyages of Zheng He, born about 200 years after Marco Polo, involved explorations of Southeast Asia and eastern Africa.
It seems to me this is another clash of idealistic vs. realistic animal advocates. The idealists wish to see wild horses living free, uninterrupted lives in untouched habitat. The horses would live out their life cycles as nature intended, with no interference by ranching, mining, oil, etc. interests. This is of course what we would all want if we had the choice.
However, the realists see that exploitative industries still have a final say over the fate of the horses, and are going to kowtow to the far more moneyed industries, and would rather see these horses contracepted than rounded up and placed in pens or slaughtered. Right now, this is the world in which we live–industry has the final say and any animal who doesn’t “contribute” to industry–such as cattle who are sold for meat–will be considered a liability and is open to destruction.
Craig C. Downer says
It is such a shame to humanity that it cannot bring itself to adequately share the land and freedom with such a wonderful presence as the horses. They have done so much for us, now isn’t it high time we do something truly good for them, like giving them adequate space and appropriate habitat and resources for truly long-term viable populations, not mere token population levels that are set ups for their decline and dieout?! Let’s change our own hangups on old outmoded lifestyles that due to moral laziness we try to perpetuate even thought, as has been proven, such are killing life on Earth! PZP is not the answer. The wild horses are underpopulated, not overpopulated. We need to employ the sound principles of Reserve Design for truly long-term viable, ecologically well adapted (to each particular unique ecosystem), and naturally self-stabilizing populations. Please see my book particularly Chapter IV where I more fully describe Reserve Design and why it is the true fulfillment of the Wild Free-Roaming Horses and Burros Act of 1971. It is an ebook and in print book and it has recently been updated and improved . The title is The Wild Horse Conspiracy and it is available on amazon and barnes and noble or through my webpage thewildhorseconspiracy dot org
Priscilla Feral says
Spare us The realists vs idealists simplification. This is a justice issue and if folks are not willing to fight for wild horses on federal public lands to be free from opportunists and commercial purveyors, then kindly get out of the way. Friends of Animals has a fire in its belly to free wild horses from the machinations of the rancher-dominated BLM. And each intervention is proof of such action. More than talk and photos, a reprehensible wrong needs to be exposed and made right. We have the passion and resources to lead where others fold.
Merritt Clifton says
This is a justice issue for those who perceive it as a justice issue. This is an “availability of resources” issue for those who realize that the present drought conditions and likelihood of worse due to global warming are rapidly shrinking the carrying capacity of the West for all large mammals, both wild and domestic. This is also a “prevention of suffering” issue for those who realize (and have seen) the consequences when the numbers of animals in a habitat come to exceed the carrying capacity. Further to be recognized in addressing the wild horse issue is that it is for the ranchers a property rights issue, which from their perspective is also a justice issue. Reaching viable solutions and accommodations within the framework of law and democracy requires recognizing and responding effectively to the concerns of all interested parties.