WASHINGTON — U.S. Sen. Mary Landrieu filed bipartisan legislation Wednesday that would prevent horse slaughterhouses and ban the exporting of horses for slaughter.

Landrieu’s new Safeguard American Food Exports Act is designed to protect horses. The bill comes in the wake of Europe’s horsemeat scandal that started early this year when testing in Ireland showed some beef products also contained equine DNA.

The controversy spread across the continent and has harmed consumer confidence. Well-known restaurants such as Burger King and Taco Bell in Europe have found tainted meat.

“Horse meat, unlicensed and not in a very transparent way, has found its way into the food supply,” said Landrieu, D-La. “The problem with that is there are very few regulations of drugs that are given to horses to race, to provide security, to work. There are drugs that are allowed for horses that are absolutely prohibited in any other animal that is consumed for human consumption.”

Of particular concern is the animal painkiller, phenylbutazone, or bute, that is considered harmful to humans.

Landrieu, a longtime horse-riding enthusiast, has repeatedly pushed for a ban on slaughtering the animals for meat that is exported mostly to Europe and Asia. She is again increasing her efforts now that plans are in the works to open the nation’s first horse slaughterhouses since 2007.

Her previous effort was the stalled American Horse Slaughter Prevention Act.

“The issue of tainted and toxic food has the American people’s attention,” Landrieu said, arguing that polling data shows 80 percent of Americans opposed slaughtering horses.

Her new bill is co-sponsored by Sen. Lindsey Graham, R-S.C.

In 2011, Congress failed to renew a five-year ban on funding federal inspectors at horse slaughter plants in the United States.

Horses are exported to Mexico and Canada for slaughter. The meat is sent to other countries where horsemeat is considered a delicacy. About 150,000 horses are estimated to be exported for slaughter a year.

Those in favor of horse slaughter argue it is a legitimate business and that it is hypocritical for people to argue that horses must be treated differently when they eat the meat from cows, pigs and sheep that were slaughtered.

A 2011 Government Accountability Office report advised either an outright ban on horse slaughtering or to legalize it, in order to stop the negative side effects of current practices, such as increased horse abandonment, the poor condition of horses exported to be slaughtered elsewhere and the overall decline in the price of horses.

Landrieu also argued that horse slaughtering would cost the federal government more money because oversight and regulation policies and resources would have to be implemented.

Rep. Patrick Meehan, R-Pa., who is leading the House effort for the legislation, said he is concerned about the safety issues.

Racehorses, for instance, are sometimes given “remarkable combinations, including things like cocaine and cobra venom,” he said.

Meehan also said that many horses sold are being secretly bought by buyers who are putting them to slaughter or exporting them. “Until a ban is in place, every single horse is just one bad sale away from horse slaughter,” he said.

Seventeen-year old equestrian Brittany Wallace shared her story of how her horse, Scribbles, was sold to what she thought was a loving family. But then that family sold Scribbles to a horse slaughter buyer.

The Omega Horse Rescue group found Scribbles bleeding to death with a sliced artery at a slaughter auction. Wallace said she coincidentally saw a picture of her horse on Facebook when Omega Horse Rescue posted a photo of the abused animal.

The horse survived and was reunited with Wallace.

“She found me,” Wallace said, arguing that horses are intelligent animals with feelings. “She knew she was dying … and she knew how lucky she was to come home.

“If people knew more about what was happening to their horses, I feel they’d step in more,” Wallace said. “I feel like it’s America’s dirty little secret. People don’t know.”