Two weeks ago, a 7-year-old white tiger attacked and nearly killed animal trainer Roy Horn during a Siegfried and Roy performance in Las Vegas. The following day, a 425-pound tiger bit its owner in a New York City apartment.

Now Congress wants to get into the act.

Prodded by the high-profile attacks, key lawmakers in the House and Senate hope to move legislation to prohibit the interstate transport of lions, tigers, cougars and other big cats.

“Because this is an issue most people weren’t aware of until recently, it’s been made much easier because more people are aware that there’s a real problem out there,” said Sen. John Ensign (R-Nev.), a former veterinarian.

Ensign, who introduced a bill on the topic in January, said he hopes the new attention will help him move the legislation through the Senate this week.

The legislation, known as the Captive Wildlife Safety Act, bans the sale and transport of any tigers, lions, leopards, cheetahs, jaguars or cougar species, or any hybrid of lion species and tiger species.

The sponsor of the House version of the bill, Rep. Howard McKeon (R-Calif.), said the Senate vote could push House leaders to bring the bill to the floor before the end of the year.

But Ensign and McKeon face opposition from an unusual quarter — the U.S. Fish and Wildlife Service, the very same federal agency charged with protecting exotic and endangered plants and animals.

Matt Hogan, the deputy director of the agency, charges that the legislation would do little to help big cats in the wild — and would divert the service’s attention from its core duties.

“This issue is not a wildlife conservation issue,” Hogan said in an interview. “This is certainly a concern, but it’s not a Fish and Wildlife issue. It’s more an animal wildlife issue.”

Bureaucratic infighting aside, however, even Hogan acknowledges that trucking big cats across state lines is a problem.

Between 5,000 and 7,000 tigers live in the United States — about the same number that live in the wild, according to Wayne Pacelle of the Humane Society.

“For every tiger roaming free in the forests of Asia, another languishes in grim confinement in a backyard cage somewhere in America,” Pacelle said at a House Resources Committee hearing on the legislation in June.

Ensign, who opened the first 24-hour animal hospital in Las Vegas in the early 1990s, said interstate commerce of big cats is a much bigger problem than people are aware of.

“I saw this thing firsthand, it really sickens you,” Ensign said. “Even the most trained professionals get attacked. It’s very dangerous for people, and we want to stop people who don’t know what they’re doing.”

Since 1998, at least nine Americans have been killed by tigers, while scores more have been mauled, according to the Humane Society.

In March, a Hennepin, Ill., man was killed by two tigers as he moved them between cages on his property.

Last September, a young 200-pound Bengal tiger on display in a grade school classroom in California attacked and severely injured a 6-year-old boy in front of his classmates.

The Humane Society says exotic pets, such as the tiger found this month in a New York City apartment, are easy to purchase over the Internet or at illegal auctions around the country.

The real problem, however, comes when the cats grow old, and resources and training are insufficient.

A single tiger can eat up to 60 pounds of red meat a week. And the carnivores are often kept in an unsuitable environment and are eventually sold to overcrowded zoos that are unable to care for them or to rescue shelters, many of which have depleted resources.

“Citizens with big pets are time bombs waiting to go off,” Pacelle said. “I think even before [the case in New York] there was an enormously big case for the bill. This event has a potential for catalyst.”

The legislation exempts zoos, circuses and other licensed animal handlers, such as Siegfried and Roy.

Twelve states prohibit the private possession of exotic animals, and seven have a partial ban and require a license of permit to possess them.

“It’s very important that we get this done,” Ensign said.

While the legislation has languished for most of the year, the recent attacks have given Ensign new momentum. In an interview last week, the Senator said he is trying to get unanimous consent to move it through the Senate this week.

“If the Senate moves, maybe that would help ours go quicker,” McKeon noted of the House version of the legislation.

Even so, the Fish and Wildlife Service maintains that the bill would “take away attention from more pressing issues” and would not go far enough to cut down on illegal pets, according to Hogan, who testified before the House Resources Committee in June.

Hogan said the service concentrates on preventing illegal activities that jeopardize the wild populations of protected species. The proposed bill would “provide little additional protection to big cat species in the wild,” he said.

The service has a force of around 250 special agents to enforce wildlife laws and treaties that protect endangered species, migratory birds and marine mammals.

“If we are involved [with the act], some agents would be pulled off current duties,” Hogan said.