Horse advocates will mount a campaign against the proposal announced last week by the U.S. Bureau of Land Management, said Chris Heyde, deputy director of government and legal affairs for the Animal Welfare Institute based in Washington, D.C.
Agency officials said they're faced with tough choices because wild horses have overpopulated public lands in the West and they no longer can afford to care for the number of animals that have been rounded up.
But Heyde maintained the agency is seeking a "magic bullet" for budget problems caused after it began rounding up the mustangs at an unprecedented rate in recent years.
He said the roundups left too many horses for the public to adopt, requiring the agency to contract for more private long-term holding facilities.
"(The proposal) is killing pure and simple to balance the books for an agency whose reckless management has caused immeasurable harm to a national treasure at considerable cost to the American taxpayer," Heyde said.
Ron Cerri of the Rebel Creek Ranch in Orovada, president-elect of the Nevada Cattlemen's Association, said ranchers would prefer horses be adopted but euthanasia may be necessary to keep their numbers down.
"Unfortunately, it's something they'll have to consider," Cerri said. "I don't know of another solution. I understand their (activists') love of horses and stuff, but they need to come up with a solution."
Cerri criticized the agency's proposal to stop roundups of wild horses to save money. Ranchers view mustangs as competition for forage on the range.
"That would be really unfortunate," he said. "We're starting to get close to what's called 'appropriate management levels' of wild horses on the range. If we stop the roundups, that number will blow up again."
There are an estimated 33,000 wild horses in 10 Western states. About half of those are in Nevada.
The agency has set a target appropriate management level of horses at 27,000.
About another 30,000 horses are in holding facilities, where most are made available for adoption.
Lacy Dalton, president and co-founder of the Let 'Em Run Foundation horse advocacy group, urged the agency to consider alternative solutions.
They include efforts to step up birth control and legislation to provide tax breaks to large landowners willing to let horses roam on their property, she said.
"The American people have spoken — they want to preserve these wild horses," said Dalton, an Americana singer who lives near Reno.
"They are symbolic of the wildness and freedom and independent spirit of the West. We need to find ways to save them without being a burden on taxpayers," she added.
Agency officials said they stepped up the roundups in recent years because of ongoing drought that has left dwindling forage and water for the mustangs. Horse advocates insist the action was taken to placate ranchers.
Last week's announcement marked the first time the agency publicly has discussed the possibility of putting surplus animals to death.
The organization's National Wild Horse and Burro Advisory Board will consider the alternatives at its next meeting in September.
Congress unanimously passed the 1971 Wild Free-Roaming Horses and Burros Act to protect the animals.