Washington ? American cattle are eating chicken litter, cattle blood and restaurant leftovers that could help transmit mad cow disease – a gap in the U.S. defense that the Bush administration promised to close nearly 18 months ago.

“Once the cameras were turned off and the media coverage dissipated, then it’s been business as usual, no real reform, just keep feeding slaughterhouse waste,” said John Stauber, an activist and co-author of “Mad Cow USA: Could the Nightmare Happen Here?”

“The entire U.S. policy is designed to protect the livestock industry’s access to slaughterhouse waste as cheap feed,” he said.

The government is now investigating another possible case of mad cow disease in the United States. The beef cow had been tested and declared free of the disease in November, but new tests came up positive, and a laboratory in England is conducting more tests.

The Food and Drug Administration promised to tighten feed rules shortly after the first U.S. case of mad cow disease was confirmed, in December 2003 in a Washington state cow.

“Today we are bolstering our BSE firewalls to protect the public,” Mark McClellan, then FDA commissioner, said Jan. 26, 2004. The FDA said it would ban blood, poultry litter and restaurant plate waste from cattle feed and require feed mills to use separate equipment to make cattle feed. Chicken litter is ground cover for the birds that absorbs manure, spilled feed and feathers.

Graphic lists loopholes in feed ban meant to protect cattle from mad cow disease; two sizes; 3c x 3 inches; 146 mm x 76 mm; 3c x 4 1/4 inches; 146 mm x 107 mm

However, last July, the FDA scrapped those restrictions. McClellan’s replacement, Lester Crawford, said an international team of experts assembled by the Agriculture Department was calling for even stronger rules and the FDA would produce new restrictions in line with those recommendations.

Today, the FDA still has not done what it promised to do. The agency declined interviews, saying in a statement only that there is no timeline for new restrictions.

“It’s just a lot of talk,” said Rep. Rosa DeLauro, D-Conn., a senior House Democrat on food and farm issues. “It’s a lot of talk, a lot of press releases and no action.”

Unlike other infections, bovine spongiform encephalopathy – also known as BSE or mad cow disease – doesn’t spread through the air. As far as scientists know, cows get the disease only by eating brain and other nerve tissues of already-infected cows.

Ground-up cattle remains left over from slaughtering operations were used as protein in cattle feed until 1997, when an outbreak of mad cow cases in Britain prompted the U.S. to order the feed industry to quit doing it. Unlike Britain, however, the U.S. feed ban has exceptions.

For example, it’s legal to put ground-up cattle remains in chicken feed. Feed that spills from cages mixes with chicken waste on the ground, then is swept up for use in cattle feed.

Scientists believe the BSE protein will survive the feed-making process and may even survive the trip through a chicken’s gut.

That amounts to the legal feeding of some cattle protein back to cattle, said Linda Detwiler, a former Agriculture Department veterinarian who led the department’s work on mad cow disease for several years.

“I would stipulate it’s probably not a real common thing, and the amounts are pretty small,” Detwiler said. But still, if cattle protein is in the system, it’s being fed back to cattle, she said.

Cattle protein also can be fed to chickens, pigs and household pets, which presents the risk of accidental contamination in a feed mill.

Rendering companies, which process slaughter waste, contend that new restrictions would be costly and create hazards from leftover waste. They say changes are not justified.

“We process about 50 billion pounds of product annually – in visual terms, that is a convoy of semi trucks, four lanes wide, running from New York to L.A. every year,” said Jim Hodges, president of the meatpacking industry’s American Meat Institute Foundation.