A synopsis of a presentation to veterinarians during The American Mustang session at the 2014 American Association of Equine Practitioners Convention, held Dec. 6-10 in Salt Lake City, Utah.
Feral tribal horses walk the streets within the Navajo Nation. They’re outside restaurants. In people’s yards. There are just too many horses, and the Navajo government is working to change that. It started in 2013 with community roundups and a veterinary management program.
Scott Bender, DVM, works as tribal veterinarian with the Navajo Nation Veterinary Program and is a USDA Animal and Plant Health Inspection Service consulting veterinarian. At the 2014 American Association of Equine Practitioners Convention, held Dec. 6-10 in Salt Lake City, Utah, Bender shared the challenges faced when managing feral horses within the Navajo Nation and results of tribal equine population management efforts.
The Navajo Nation is located in the southwestern United States, with territory spanning Arizona, Utah, and New Mexico. The reservation comprises 18 million acres and, said Bender, an estimated 75,000 to 96,000 horses.
The tribe permits 12,000 livestock owners, with the majority of permit holders having one to five privately owned horses.
Under tribal law, all unbranded horses within the Navajo Nation are tribal property, Bender explained. That leaves the tribe with a lot of horses.
The Navajo traditionally view horses as sport, working, and food animals. “The horse is sacred to the Navajo, but that doesn't mean we don't eat them," Bender explained. The Navajo believe horsemeat has medicinal, healing properties and is useful as a “winter” meat, he said, explaining that “horsemeat, by tradition, can only be eaten in the winter between October and April—end of thunder and not after ‘first thunder.’”
Initially and into the early 20th Century, the U.S. Bureau of Indian Affairs managed tribal livestock, but management has slowly transitioned to the sovereign nation government, Bender said. This happened partly because of U.S. government-approved reduction of livestock in the 1930s and the euthanasia and burial of more than 500 horses by federal authorizes following a dourine outbreak at the Canyon de Chelly National Monument, which is located in northeastern Arizona within the Navajo Nation boundaries. “This ‘waste of resources’ has left a negative indelible mark on the attitude of Navajo livestock owners toward the U.S. government,” Bender said.
To the Navajo, unused horsemeat is a wasted resource that the creator gave the people, he clarified.
With this in mind, surplus Navajo horses had historically been sold off-reservation to slaughter as a way to manage populations and produce income. When U.S. equine slaughter plants closed in 2007, the tribal horses lost 95% of their value and the surplus feral horses were left to breed without human controls, Bender said. “The current (tribal) horse issue is a direct result of the elimination of an outlet for surplus horses,” he added.
As herds grew, damage to rangelands increased, as did horse-caused human injuries. “Horses in right-of-ways caused car wrecks, human injuries, and even deaths,” Bender said. These issues led tribal communities to request that the Navajo National Department of Agriculture start its equine population management program in 2013, which involved roundups and veterinary services, including free:
While the initial fertility vaccination was effective, Bender described owner booster rates of horses as “dismal,” despite the program’s outreach and communications efforts promoting boosters. The program’s leadership is now investigating anti-gonadotropin-releasing hormone vaccine (know more commonly as anti-GnRH or GonaCon) use as a longer-activing and single-dose alternative to PZP.
In 2013 the Navajo Nation local communities, with the help of the Navajo Nation Departments of Agriculture and Resource Enforcement, rounded up more than 8,900 horses. Permitted owners claimed approximately 250 horses, with the tribe selling the rest with the requirement that they could not be returned to the Navajo Nation.
The veterinary program’s goal was to castrate 1,000 male horses and vaccinate 1,500 mares against fertility by the end of 2014. To date, more than 700 horses have been castrated or vaccinated with PZP for fertility control. Bender said members of communities where horse removals took place have reported improved forage conditions in spite of the continuing 14 years of drought in the southwestern United States and Navajo Nation.
Source: The Horse
The National Park Service (NPS) is currently studying the use of fertility control vaccines to control feral horse populations on NPS lands.
Jenny Powers, DVM, PhD, an NPS wildlife veterinarian, shared preliminary results during a presentation at the 2014 American Association of Equine Practitioners Convention, held Dec. 6-10 in Salt Lake City, Utah.
Managers at Theodore Roosevelt National Park in North Dakota are seeking ways to control feral horse populations that include alternatives to helicopter roundups and sales.
The horses, which some consider culturally significant and suggest are the origin of the Nokota breed, share the same range as elk, pronghorn, mule and white-tail deer, and bison in the 46,000-acre park, necessitating careful resource allocation and equine population management, Powers said.
In October 2009 NPS started a study using a gonadotropin-releasing hormone (GnRH) immunocontraceptive vaccine on mares in the park. First, park managers rounded up and removed half the park’s horses. They then blocked the remaining mature mares by age, body condition, and reproductive status. They separated the horses into a treatment group of 29 and a nontreatment group of 28 individual mares.
The treatment group received 2 mL of GnRH vaccine. The control group received 2 mL of saline. Most mares were pregnant at the time of treatment. “The GnRH vaccine we used showed promise as a multiyear vaccine after giving a single dose," Powers said. "This is highly unusual for a vaccine to work for more than a year and would greatly improve the efficiency over currently available fertility control vaccines.”
Over the next four years, NPS researchers observed the mares for:
In the first foaling season, 2010, researchers saw no statistical change in foaling or foal survival rates, as was expected because most animals were pregnant at the time of vaccination, and there was no difference in foal survival between treated and control mares, Powers said.
In the second foaling season (the first expected to be affected by vaccination), the proportion of treated mares that foaled was 35% less than untreated mares. The third foaling season saw the proportion of treated mares that foaled 30% less than untreated mares. But the fourth foaling season, researchers observed no statistical difference in foaling rates between treated and untreated mares.
NPS managers observed minimal changes to reproductive behaviors or time budgets, Powers said. Of the treated mares, 80% had injection site swelling one to four years after treatment.
Overall, NPS researchers found a single vaccination with the GnRH vaccine provided a modest decrease foaling rates for two years post-vaccination and had little effect on social behaviors, she said, adding that treated mares had no more or less reproductive interaction with stallions than untreated mares.
She also said treated mares did have apparent inflammatory reactions at injection site, but this did not appear to affect their well-being, as they did not become lame or lose body condition.
“The NPS is currently studying the efficacy of revaccination four years after the first vaccination, and researchers are interested in how long a booster vaccine might last and how effective it can be at preventing pregnancy,” Powers concluded.
Source: The Horse
Click Here to view white paper, presented at the AAEP conference
A group advocating for Alberta’s free-roaming horses has entered into an agreement with the province to “humanely manage” the population by starting both contraception and adoption programs.
The memorandum of understanding between Alberta Environment and Sustainable Resource Development and the Wild Horses of Alberta Society will allow the group to help manage horses in the Sundre area.
“It’s a five-year agreement,” said Duncan MacDonnell, spokesman for Alberta Environment. “The agreement allows Wild Horses of Alberta Society to undertake two experimental programs to help control the wild horse populations.” But it doesn’t necessarily preclude another capture season this spring, he said, noting that decision is still pending.
Provincial officials have maintained the horse population needs to be balanced with the health of the grasslands — a position that led to controversy last spring as the province allowed a six-week capture season for up to 196 horses that could be kept for personal use or sent for slaughter. Only 15 animals were rounded up by two ranchers, but it led to protests by wild horse advocates, who suggested there were fewer animals than the province reported.
The official 2014 count showed there were 880 horses in the foothills between Kananaskis Country and Sundre, down about 100 horses from the previous year. It led activists and conservationists to suggest last spring’s capture season was unnecessary.Throughout the debate, others suggested the province try other methods to manage the population.
The agreement between the province and the Wild Horses of Alberta Society includes a contraception program targeting female horses and an adoption program allowing the organization to take in and adopt out any young horses.
Bob Henderson, president of the society, couldn’t be reached for comment, but a news release issued by the group said it’s excited about the opportunity to help manage the horse population. It noted that the contraception program will select a limited number of mares to receive a vaccine to prevent pregnancy for up to three years without disrupting the herd structure and dynamics.
The adoption program will allow the group to take in any young foals that have been abandoned or injured. It also allows rescue of any horses that stray onto private land or roadways. The programs will all be run on donations from the public, including eight hectares of land, where a safe handling facility will be built.
Officials with the province said the Wild Horses of Alberta Society will be required to show results from both programs over the five-year period.
Source: Calgary Herald by Colette Derworiz