Two recent documents are drawing renewed attention to the federal government's wildlife damage control program.

One is a bipartisan letter from four members of the U.S. House of Representatives requesting a congressional investigation of Wildlife Services, a U.S. Department of Agriculture agency that specializes in killing birds and mammals considered a threat to livestock, the public and the environment.

The other is a "notice of violation" this month fining an employee of the agency $2,400 for placing a spring-loaded sodium cyanide ejector near a family's home in Texas, which killed their dog. Earlier this year, a bill was introduced in Congress that would ban the devices, which have killed more than 3,400 non-offending animals by mistake since 2006, including 250 dogs, records show.

"Why would they put something out that would target animals that are no danger to anything?" said J.D. Walker, a car dealership manager whose dog was killed by the agency's poison southeast of Abilene last year. "It makes absolutely no sense."

Michael Bodenchuk, state director of Wildlife Services in Texas, said the employee is appealing the fine and that the cyanide devices are a "cost-effective" tool for killing coyotes.

"They've been through multiple reviews by EPA," Bodenchuk said, referring to the U.S. Environmental Protection Agency. "EPA has decided not to ban them in the past, and we use them as efficiently as possible."

Known as M-44s, the devices are coated with strong scent to attract wildlife and fire poison into the mouth of whatever tugs on them. Used mainly to control coyotes, they have accidentally killed many other species over the years, including black bears, raccoons, ravens, bobcats, kit foxes, wild pigs, opossums and federally protected bald eagles.

At least 18 agency employees and several members of the public have been exposed to the poison, too. None died, but many were treated for nausea, blurred vision and other symptoms.

"They need to figure out a different way," said Angel Walker, J.D.'s wife. "There are other things that can keep wildlife away from animals and not put children or domesticated animals in harm's way."

After two days of searching, she discovered her dog's body near an M-44 about 900 feet from their home. "It was a horrible thing," she said. "She had thrown up. You could tell it had been a horrible death. It was really, really heart-wrenching … . I was just lucky it was my dog and it wasn't my son."

The agency's toll on non-target species – a subject explored in a series of stories in the Bee this spring – is one of several issues cited in a bipartisan letter June 8 requesting a congressional probe of the agency.

"Information recently brought to light in the Sacramento Bee … documents many serious problems that reinforce our existing concerns about Wildlife Service's operations, especially its lethal predator control activities," the letter says.

"Employees routinely hide non-target animals killed, encouraged by supervisors and the agency's culture … ," the letter adds. "While even the military allows the media into the field, Wildlife Services does not."

The letter to Darrell Issa, R-Vista, chairman of the House Committee on Oversight and Government Reform, is signed by John Campbell, R-Irvine, and Peter DeFazio, D-Oregon – who last month said they intended to request an investigation formally – along with Elton Gallegly, R-Simi Valley, and Jackie Speier, D- Hillsborough.