Horse News

Friends of Animals files lawsuit to cancel registration of wild horse fertility control pesticide PZP

Volunteer takes aim with PZP dart gun (photo BLM)

Source:  Friends of Animals

For Immediate Release
July 26, 2016
Jenni Best, associate attorney, FoA’s Wildlife Law Program 720.949.7791;
Mike Harris, Director, Wildlife Law Program; 720.949.7791;
FoA files lawsuit to cancel registration of wild horse fertility control pesticide PZP
(Washington, D.C.) Friends of Animals (FoA) has filed lawsuit against the U.S. Environmental Protection Agency (EPA) for failing to respond to the organization’s legal petition in May of 2015 that the agency 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 (HSUS) in 2012.
Information is now available to the EPA regarding the unintended—and previously undisclosed—side effects on both targeted mares and wild horses in general. It not only shows unreasonable adverse effects, but also indicates the use of PZP on wild horses likely violates the Wild Horse and Burro Act of 1971.  FoA’s lawsuit requests that the Court order the EPA to make a final decision regarding the petition within 60 days.
“Through this action, FoA hopes to force EPA to reopen the registration process for PZP so the agency can adequately consider this new scientific research.  If this research is legitimate, and we fully believe it is, use of PZP on wild horses is likely illegal under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA),” said Michael Harris, director of FoA’s Wildlife Law Program.
“When the HSUS applied to EPA to register PZP, the organization was so excited that PZP was effective at preventing pregnancy in mares that it failed to evaluate whether the forced drugging of horses could negatively impact individual animals or the herd.  Indeed, the majority of research submitted by HSUS was published by the late Dr. Jay Kirkpatrick, a veterinarian who manufactured PZP, and who never studied the biological, social and behavioral effects the drug can have on wild horses.”
Since EPA originally granted the registration, independent research has been published identifying previously undisclosed effects of PZP on wild horses. Among the findings, it is now known 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.Over a decade ago, experts warned that the majority of wild equid populations managed by the BLM are kept at population sizes that are small enough for the loss of genetic variation to be a real concern.
Since 2012, the Bureau of Land Management (BLM) has administered approximately 2,407 doses to wild mares on public lands in the United States. BLM has repeatedly asserted in 2016 that it intends to increase its use of PZP as a means of controlling wild horses, particularly in western states like Wyoming, Utah and Nevada where wild horses are seen as pests by local ranchers desiring to utilize public lands for cattle and sheep grazing.
“Proponents of PZP have coerced the EPA into thinking that wild horses are nuisances and pests that need to be controlled and managed. If the Bureau of Land Management continues its violations against wild horses—roundups and forcibly drugging mares with PZP—we expect wild horses will go extinct on federal public lands,” said Priscilla Feral, president of Friends of Animals. “Anyone supporting those physical assaults is morally bankrupt and undermines the integrity and importance of wild horses. Our definition of wild means no human exploitation and manipulation of free-roaming animals. It’s time to remove the actual culprits of land degradation from herd management areas—cattle and sheep.”

17 replies »

  1. Our wild burros are being PZP’d also and FOA’s original petition to the EPA requested …
    “that the Administrator Conduct a Special Review to Consider Scientific Evidence Demonstrating the Need to Cancel the Registration of the Contraceptive ZONAST-H for Population Control of America’s Wild Horses and BURROS.”

    Liked by 1 person

  2. Our wild horses and burros dont have enough trouble staying alive? They need this like they need a hole in the head. What would FoA propose to do to keep them on the range? Abstinence?

    Liked by 2 people

  3. Kirkpatrick, originally from Bucks County, Pennsylvania, spent seven years as a National Park Service ranger in Rocky Mountain National Park, Colorado, before earning a Ph. D. in reproductive physiology from the College of Veterinary Medicine at Cornell University in 1971. He’s as close as possible to being a veterinarian without a formal degree in it. He worked with non-human animals in zoos, wildlife on ranges, and domestic animals – who do not respond well to Pzp. After 40 years of doing this, you’d think he’d study the offspring of female animals treated with his concoction, but chose not to do so. Pzp remains a pesticide with side effects and actually extends the breeding season. For whitetailed deer, the stuff extends breeding by 90 days without results, and they cannot be hunted for their meat. Too bad for those glorified “hunters”.

    Liked by 3 people

  4. Congress unanimously voted to Protect FREE ROAMING WILD Horses and Burros in 1971 but US Fish and Wildlife Services failed to PROTECT and LIST them under the 1973 Endangered Species Act which provides critical habitat (ACECs) for “protected” Native American species of special Interest. This is the underlying issue regardless of PZP.

    Liked by 1 person

  5. I don’t see how FoA is going to accomplish much of anything through this lawsuit. Even if they win, all that will happen is that PZP will be banned. It won’t stop removals nor will it prevent the probability of our beloved wild ones from being killed.

    If we as advocates want to pick a winning battle, we would petition Congress to audit the scientific defensibility of the BLM’s AML’s. I say this because according to the National Academy of Sciences’s 2013 report on the BLM’s Wild Horse and Burro Program, it quotes, “How Appropriate Management Levels are established… is not… supported by scientific information.” If Congress finds that AML’s can support more horses than the BLM claims they can, it could mean that horses and burros won’t be subjected to mismanagement. This is something both pro- and anti-PZP advocates can agree upon.

    Liked by 3 people

  6. I wish that FOA would spend even half the time, money, energy working to actually save the lives of our wild horses and burros. Right now they are facing possible slaughter, being killed at the holding facilities they are being warehoused in, having 80% of the horses remaining on public lands being sterilized and being shipped overseas – these are all suggestions by the BLM that Congress is considering right now and will act on with the 2019 Budget. Instead of “protecting” our wild horses and burros from the “horrors” of PZP how about doing something useful and WAKING UP and fighting to save their lives?

    Liked by 1 person

    • Different battles, same team, same war. Your efforts address those living today, while it seems FOA is looking pointedly towards the future. Neither is wrong, and in fact both are not only good but needed. We need all hands on deck.

      As I see it, both efforts are fighting to “actually” save the existence of our remaining wild horses and burros in the ways they are able.

      Kudos to all willing to stand up and face the foe.

      Liked by 1 person

  7. We all realize there is NO over-population – only BLM propaganda. BUT honestly, making the fight to save the horses all about PZP – doesnt end up saving them. Stopping the use of PZP will only give the haters one more reason to remove wild horses from the range, using more of the over-population excuse. This argument only separates the different wild horse organizations & prevents them from working together! Everyone seems to have their own agenda & THAT doesnt appear to be the safety of wild horses & burros. Proving which agenda is “right” really doesnt save the horses!

    Liked by 1 person

  8. 1. Overpopulation is a false flag. On the range, wild horses are few and far between. Off the range, half of them are missing. It is wrong to promote birth control per BLM’s falsified data, on herds “managed” below minimum-viable population. That approach just enables BLM’s corrupt practices to continue and drives the herds off the genetic cliff. As for wild burros, even while acknowledging that they are not overpopulated, HSUS is conducting PZP-experiments on the Black Mountain herd.

    2. Registered without testing: Friends of Animals has challenged the legality of EPA’s registration of PZP because the agency approved the pesticide without investigating its toxicity and ecological impact.

    3. How It works: Contrary to the manufacturer’s sales-pitch — that PZP’s antibodies merely “block sperm attachment” — independent researchers found that its true mechanism-of-action is to provoke disease. Behaving like a perverted vaccine, PZP tricks the immune system into producing antibodies that cause ovarian dystrophy, autoimmune oophoritis, ovarian cysts, and premature ovarian failure. [Please see Kaur & Prabha (2014); Curtis et al. (2007); Mahi-Brown et al. (1988); Nettles (1997); Rhim et al. (1992); Sehgal et al. (1989); and Stoops et al. (2006).]

    4. Out-of-season births: Ransom, Hobbs, and Bruemmer (2013) conducted a longitudinal study of 3 wild-horse herds currently contracepted with PZP: Pryor Mountain, Little Book Cliffs, and McCullough Peak. They found that foaling was occurring nearly year-round rather than pulsing normally in Spring. Nettles (1997), too, had reported unusually-late foaling-dates where PZP was in use.

    5. Slow return to fertility, if ever: Ransom et al. also found that, after stopping PZP, it takes, on average, 1.13 years per each year-of-treatment before mares regain fertility. PZP’s manufacturer admitted it could take up to 8 years after just 3 consecutive treatments. Knight & Rubenstein (2014) found that administration of the first dose before puberty sometimes triggered sterility.

    6. Endangered fillies: BLM administers PZP to Pryor Mountain’s fillies starting at age 1½. BLM artfully describes them as “becoming two year olds.” However, Feist & McCullough (1976) found that most Pryor Mountain fillies did not reach puberty until age 3. Please recall Knight & Rubenstein’s finding (above). The fillies continue to receive PZP injections for four consecutive years before treatment is paused. Per Ransom et al., they would be expected to need 4½ years to regain fertility while, per the manufacturer, it could take 8 years. But BLM’s protocol gives them only 5 years off PZP before they are put back on it again permanently. Because PZP wears off unpredictably, that brief window-of-fertility could close before they produced a foal. If so, their genetic contribution would be zero.

    7. Concern that PZP selects for weak immunity (Gray & Cameron, 2010): PZP works best — meaning, sterilizes faster — in mares whose immune-function is strong, but it may not work at all in mares whose immune-function is weak. Ransom et al. had to eliminate 7 mares from consideration because they birthed foals every year, despite PZP. Their foals likely inherited weak immune-function. Over time, a PZP-treated herd thus becomes populated with horses less-able to resist disease.

    8. Dubious “benefit” of increased longevity: Exceptionally-long life — for a wild horse, that means more than 15 to 20 years — is an ironic effect of PZP. The manufacturer actually boasted about it, as if it were a good thing. However, other scientists expressed concern (Gray & Cameron, 2010; Knight & Rubenstein, 2014). Ultra-elderly mares continue to consume resources, but no longer contribute to the gene-pool. It is detrimental to the genetic viability of a size-restricted population to carry sterile herd-members way-beyond their normal life-span.

    9. Hazardous, especially to women-darters: EPA’s Pesticide Fact Sheet advises that Personal Protective Equipment requirements include long sleeved shirt and long pants, gloves, and shoes plus socks to mitigate occupational exposure. Note that the darters pictured above are not wearing gloves. They have been lulled into a false sense of safety because the manufacturer claimed PZP is “so safe it is boring.” Independent research shows otherwise — that PZP is a powerful hormone-disruptor.

    10. Predators, not PZP: Nature provides the perfect agents to perform population-control of wild horses — carnivores. Mountain lions, bears, wolves, and coyotes can — if allowed to — efficiently do the job. Predators promote survival-of-the-fittest, thereby helping to bring about the “thriving natural ecological balance” that BLM claims is the goal. Cost: $0.

    Liked by 2 people

  9. It’s possible that Friends of Animals is cutting a much broader swath with the PZP lawsuit as it is currently being used by other agencies on other species of wildlife as well.

    BLM quietly unveils its wild horse extinction plan to Congress
    Posted by Meghan McIntire on 05/01/2018
    The Bureau of Land Management will not rest until wild horses are extinct.

    That’s clear in its recent report it quietly sent to Congress outlining management options for a “sustainable wild horse and burro program.”
    What’s also never been clearer is BLM’s roots in the meat industry, it evolved from the United States Grazing Service, which as the name suggests, catered to cattle and sheep ranchers.

    Decades later, the agency is still wedded to the meat industry.
    That’s why Friends of Animals is not surprised this “report” calls for massive removals, permanent sterilization, sale without limitation and slaughter. It even mentions that at the National Wild Horse and Burro Summit in August, there was overwhelming support for commercial use of wild horses for pet food and to feed zoo animals.

    But what’s missing in the 24 pages is the truth-that commercialized Western public lands is the real problem, not the wild horse population. Upwards of 2 million cattle graze public lands, and the government has authorized thousands of oil, gas and mineral extraction projects on these areas as well. These activities are the real cause of range degradation, and have substantially fragmented and reduced habitat left for wild horses.
    The Wild Horse and Burro Act of 1971 does not establish mechanisms to ensure adequate habitat for wild horses-since its passage wild horses have lost 41 percent of their habitat, more than 20 million acres. Of the 245 million acres of public land managed by the BLM, 155 million is open to livestock grazing. By contrast, wild horses are restricted to just 26.9 million acres, which they must share with livestock.

    The report, which laments the cost of the wild horse and burro program, also fails to mention that U.S. taxpayers had lost more than $1 billion over the past decade because of livestock grazing on public lands, according to a 2015 study. In 2014 alone, taxpayers lost $125 million in grazing subsidies on federal land.

    Six states have already lost their wild horse populations: Missouri, Iowa, Arkansas, Texas, Oklahoma and Kansas. Montana only has a paltry 166 left.
    BLM, which ignores the fact that wild horses do have natural predators and do succumb to old age and environmental stressors, will not be happy until wild horses are extinct.

    So if America wants to save the horses and other wildlife on our public lands, we need an honest discussion in Congress about reforming laws that allow for unbridled development at the expense of wildlife.

    Congress should also consider amending the WHBA to allow wild horses to be returned or relocated to Herd Areas in states where wild horses have been wiped out. Another amendment should restrict cattle and sheep from grazing in wild horse Herd Management Areas.

    Liked by 5 people

    • I understand that this lawsuit was initiated in 2016 but although not “new” it is still ongoing and current.


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