It was a productive day for Gary Strader when he pulled his vehicle up to a remote site in northeast Nevada and found nine coyotes caught in leg hold snares set by the federal government. As was routine, Strader, a former trapper with the U.S. Department of Agriculture, signaled his dogs to attack.

It was a productive day for Gary Strader when he pulled his vehicle up to a remote site in northeast Nevada and found nine coyotes caught in leg hold snares set by the federal government. As was routine, Strader, a former trapper with the U.S. Department of Agriculture, signaled his dogs to attack.

His supervisor, who had accompanied him that day, watched and laughed as the dogs circled the coyotes and ripped into them, Strader recalled.

“That was regular practice,” said Strader, who in 2009 left Wildlife Services, a little-known program within the USDA. The program is tasked with humanely killing wildlife seen as a threat to the environment and livestock, as well as protecting the public from wildlife hazards to commercial planes at airports.

“You let your dogs fight with them. That was part of the job,” said Strader. “There’s not a person in Wildlife Services who is not aware of it.”

The brutal approach by Wildlife Services is part of a culture of animal cruelty that has long persisted within an agency that uses taxpayer money to wage an unnecessary war on wildlife, according to two U.S. congressmen who have repeatedly called for a thorough investigation.

“This agency has become an outlet for people to abuse animals for no particular reason,” Rep. John Campbell, R-Calif., told FoxNews.com. “It is completely out of control,” he said. “They need to be brought into the 21st century.”

Campbell and Rep. Peter Defazio, D-Ore., penned a letter last November to Agriculture Secretary Thomas Vilsack calling for a complete audit of the “culture” within Wildlife Services – in particular its lethal Predator Control program – by the USDA Office of Inspector General.

Vilsack responded in a letter dated Feb. 1, saying an investigation into animal cruelty allegations was under way by the Administrative Investigations and Compliance Branch of the USDA’s Animal and Plant Health Inspection Service.

“USDA does not condone any form of animal cruelty and holds all employees responsible for adhering to Departmental and Agency standards and directives,” Vilsack wrote. “WS personnel are expected to use approved and humane methods to euthanize captured or restrained animals whenever practicable, and in accordance with American Veterinary Medical Association guidelines.”

But the lawmakers say several serious questions remain unanswered.

“I don’t understand why it should be the responsibility of the federal government to attempt to – very ineffectively and, in fact, probably detrimentally – remove wildlife that has not been implicated in attacks on people and cattle,” said Defazio, who for two decades has championed the defunding of Wildlife Services.

Evidence showing animal cruelty has not been difficult to uncover.

In October, photos were discovered on the personal Facebook account of Wildlife Services employee Jamie P. Olson. The images showed dogs snarling at and biting into live coyotes trapped in steel foot-holds, as well as pictures of coyote carcasses. The photos were allegedly posted in an album titled “work,” but it remains unclear whether they were taken while Olson was on the job or not.

Olson, who works for Wyoming Wildlife Services, is still employed, but the matter is being investigated, according to Carol Bannerman, a spokeswoman for the USDA’s Animal and Plant Health Inspection Service, which oversees Wildlife Services.

Wildlife Services declined to make Olson available for comment, citing the ongoing investigation.

When asked whether it was acceptable practice to have dogs attack trapped animals, Bannerman responded: “In terms of a trapped animal, that would be considered unacceptable.”

Bannerman explained that Wildlife Services regularly educates ranchers on various non-lethal methods that can be used to protect livestock – including better fencing, guard dogs and night patrols.

But, she said, “Sometimes ranchers will come to us at a point and say, ‘Okay, we’re trying all these things and we’re still experiencing a loss.”

To the farm industry, predator control is a critical factor in maintaining the success of the nation’s agriculture.

“We do not condone inhumane or cruel treatment of any animals,” said Paul Schlegel, director of public policy for the American Farm Bureau Federation. “At the same, our farmers and ranchers recognize the important role played by USDA’s Wildlife Services office.”

“Livestock producers and row crop farmers all have significant investments in the land and in producing the food and fiber upon which millions of Americans depend,” Schlegel said. “We support effective predator control programs that assist farmers in bringing their products to market and recognize the important role those programs play in helping to feed and clothe America.”

But Campbell and Defazio, as well as various environmental groups, claim the government’s mission is excessive and cruel – and argue it should not be the taxpayers’ responsibility to protect private land and livestock.

Strader’s statements, for example, illustrate a particularly dark side of the agency’s killing methods.

“They wanted every single coyote killed,” he said.

Strader said he was often tasked with hunting for coyote dens while working for the government in remote areas of Utah and Nevada. He described how he would lower his stethoscope into the hole and listen for breathing or whining from the coyote puppies. Then he would drop a phosphorus bomb into the den and cover its opening with dirt.

“The bombs burn so fast and so hot that it sucks all the oxygen out of the hole,” he said. “They suffocate.”

“I had to kill hundreds of coyote pups and pregnant females,” Strader continued. “If you found a coyote den, you just bombed it.”

Strader, as well as several others, including a management source within the USDA, also charged that Wildlife Services employees often do not abide by trap-check laws — meaning animals can be left for days in traps where they die from starvation or the elements.

Strader claims his job was terminated in 2009 after he alerted supervisors to alleged wrongdoing within the agency. He said his views on trapping animals have changed since he left.

Coyotes primarily feed on small mammals, like rabbits, rodents and squirrels, but they can also prey on larger animals like deer and livestock. Biologists say natural predators, like coyotes, are vital to a healthy ecosystem because they keep other species’ populations down. And the more coyotes that are killed, the more coyotes will reproduce. If a member of the pack is killed, for instance, the alpha female responds by producing more litters.

“Not only is this ethically indefensible, it’s ecologically insane,” Camilla Fox, executive director of Project Coyote, said of the killings each year by the predator control program.

A culture of cruelty has existed within the agency for decades, according to critics.

Rex Shaddox, a Texas law enforcement officer who worked for Wildlife Services in the 1980’s, said he left the agency – which at the time was called Animal Damage Control – after a particularly disturbing occurrence.

Shaddox said he and other workers were ordered to report to a city dump in Uvalde, Texas, to witness agency officials experiment with M-44 sodium cyanide on dogs from a local pound that were supposed to be euthanized.

“We were told to watch as they held the dogs down and shot cyanide into their mouths, one by one,” he said. “I went home and cried that day. And then I quit.”