Leonhard Foeger / Reuters

An employee of the microbiological laboratory of the Austrian Agency for Health and Food Safety prepares a sample of minced meat in Vienna this week. The samples of minced meat are tested for the presence of horse meat as a precaution. United States officials say it's highly unlikely the scandal will reach U.S. consumers.

Europe’s scandal over horse meat hidden in beef products -- including recalls of Nestle ravioli and Birds Eye chili con carne -- has renewed questions about whether Americans unwittingly could be eating equine products as well.

U.S. Department of Agriculture regulators say it’s highly unlikely that beef adulterated with horse meat could make it to the nation’s dinner plates because no domestic suppliers currently slaughter horses and the agency has strict labeling and inspection standards for imported meat.

But agency officials also acknowledge privately that species testing for meat imported into the U.S. is performed typically only when there’s a reason to question a shipment.

And a Florida company that supplies the only validated tests for horse meat in food has been slammed with nearly 1,000 requests in recent weeks for its $500 kits -- including orders from major U.S. meat producers.

“It’s becoming a little hectic,” said Natalie Rosskopf, administrative director of Elisa Technologies Inc. of Gainesville. “There was no call for horse testing a month ago. Nothing.”

Continental Europe has been roiled recently by reports of horse meat masquerading as beef in frozen burgers and prepared foods, including frozen dinners and pastas. This week, Nestle announced it was removing chilled pasta products produced by a German supplier, including Buitoni Beef Ravioli and Beef Tortellini, from stores in Italy and Spain, and a lasagna product from France. On Friday, frozen food maker Birds Eye said it would withdraw products including chili con carne from Britain and Ireland because tests detected traces of horse DNA.

The trouble with horse meat hidden in beef is partly a health concern. Meats taken from store shelves in Britain and Germany had traces of a powerful equine painkiller, phenylbutazone, or “bute,” which is banned in animals destined for human food, tests showed.

But it’s also about trust, especially in the U.S., where many shudder at the mere thought of eating horse meat and the deception would raise even more suspicion about a company’s practices.

“If a company is willing to commit fraud, I can’t imagine that food safety is the biggest thing on their agenda,” said Bill Marler, a Seattle lawyer and food safety expert who publishes a blog focused on the industry.

In fact, boneless beef adulterated with horse meat -- and with kangaroo -- did make it to the U.S. more than 30 years ago, when mislabeled meat from Australia led to the impounding and testing of 66 million pounds of the product, according to old USDA records found and posted by Marler.

Known as the “Australian meat incident,” the beef substitution scandal prompted swift action and increased scrutiny by agency officials.

USDA officials couldn’t quickly produce records of species testing results in the past 30 years -- or even the past year -- but they say the possibility of that happening again is remote. The U.S. neither slaughters horses nor imports horse meat from other countries, and it doesn’t allow import of beef from the countries and companies involved in the European scandal, an official told NBC News. (He was speaking on background because he said he wasn’t authorized to discuss the issue.)

In addition, USDA inspectors look at every shipment of meat sent through U.S. ports and can demand species testing if anything is amiss, documents show.

Officials with the Food and Drug Administration, which oversees processed foods, said that they had detected no horse meat in imported or U.S.-made food. 

“We have no past record or current indication that horse meat is an ingredient in any FDA-regulated processed foods in the U.S.,” Jalil Isa, an FDA spokesman, said in an email. He added that FDA officials are reaching out to Nestle and Birds Eye to ensure that no adulterated food was sent to the U.S. Nestle has said no U.S. products use meat from European sources.

Birds Eye Iglo U.K. products have no connection to the Birds Eye brand in the U.S., which is owned by Pinnacle Foods, and isn’t affiliated with the U.K. supplier.

Producers such as the meat giant Cargill say they don’t import beef from plants that also slaughter horses, or from the companies and suppliers implicated in the European scandal, and they remain confident that their meat is free of adulteration.

“Cargill’s beef supply chain is shorter than those involved in the horse meat issue in Europe and we know, and work directly with, our suppliers, which minimizes the potential for fraudulent substitution of products,” Cargill spokesman Mike Martin told NBC News in an email.

Still, the problems in Europe could prompt renewed scrutiny, he added.

“We do not analyze for other species and are assessing the current situation to determine if this is something we might do in the future,” Martin said.

If they do, they’ll have to turn to Elisa Technologies for the horse species test, said Rosskopf. The company’s meat species kits, which verify animal proteins in raw and cooked meat samples, have been used for years by the USDA and by private firms, she said.

Before the discovery in Europe of horse meat in beef, the firm’s typical demand was for tests for more common species, for instance, to confirm that no pork was present in kosher meat, Rosskopf said. Now, meat suppliers mostly in Europe, but also in the U.S., have been clamoring for the equine test.

Have there been any positive tests so far?

“I can’t say,” said Rosskopf, noting that the company is known for its adherence to confidentiality agreements.

Of course, putting horse meat on the dinner table is common in many countries, including France, Canada, Mexico and Japan, to name a few. And it’s not unheard of on American menus, either. Slaughterhouses that produced horse meat for human consumption were in operation in the U.S. until 2007, when the last three of a one-time high of 16 or 17 plants closed under state and federal pressure.

Congress effectively banned the practice then by refusing to fund USDA inspections of the slaughterhouses. Those efforts were fueled by vocal anti-slaughter activists who regarded the practice as inhumane.

The arrangement stayed in place until 2011, when the Obama administration quietly lifted the restriction, partly out of concern for the neglect of horses in the U.S. and the treatment of horses that were shipped to Canada and Mexico to be killed.

The U.S. exported more than 46,000 metric tons of horse meat in 1990, a figure that fell to about 5,600 metric tons in 2007, when the ban was enacted, industry figures show.

Wyoming state Rep. Sue Wallis is trying to reinstate horse slaughter in the U.S. and to build a new source for the meat in America and abroad.

Her application is among those pending with the USDA to open horse slaughterhouses in Missouri, Iowa and New Mexico. The firms would produce what she and other advocates call “cheval,” horse meat that she said is prized by gourmet cooks and health enthusiasts for its taste and lean profile. Plus, Wallis said, horse meat is generally about 40 percent cheaper than beef.

“There are plenty of people in America who have no problem with cheval and are anxiously awaiting our product,” she said.

Related stories:

• 'Fraud on a massive scale:' Europe's horse meat scandal keeps growing
• British shoppers saying nay to meat after horse scandal
• Horse slaughtering legal in US, but public won't bite

Starting next year, U.S. meat producers will have to abide by a new “test and hold” rule aimed at curbing outbreaks of foodborne illness caused by dangerous bacteria in certain types of beef, poultry and other meat, officials said Friday.

The regulation, first proposed in April 2011, will require manufacturers of raw ground beef, tenderized beef and other “non-intact” beef and those who make all ready-to-eat products containing meat not only to test for disease-causing pathogens, but also to wait for the results before shipping. It takes effect in 60 days, U.S. Department of Agriculture officials said.

That’s a change in the USDA’s current policy. Now, when the agency’s Food Safety and Inspection Service staff collects samples for testing, companies are asked but not required to hold the meat until the results are known.

That has allowed bacteria -- including certain strains of E. coli, listeria and salmonella -- to contaminate meat, leading to outbreaks of foodborne illness, USDA officials said.

If the new requirement had been in place between 2007 and 2010, it could have prevented 49 of the 251 meat, poultry and processed egg product recalls that occurred during that time, officials said.

Many meat producers already have test-and-hold policies in place, and some industry trade groups, including the American Meat Institute, have supported making it a requirement.

“Consistent with our requests in 2008 and 2009, AMI has long advocated the practice of controlling tested product and not using it before test results are received,” AMI President and chief executive Patrick Boyle said in a statement. “Preventing potentially adulterated meat and poultry products from reaching consumers provides additional public health protection."

Smaller meat producers, including those who specialize in fresh ground beef, worried that the new regulations would force them to hold product too long for test results, sacrificing quality and safety, according to comments posted in response to the proposal.

But FSIS officials said they anticipate that negative test results will be determined within two days.

Related stories: 

• New beef brouhaha: Should you be grossed-out by 'meat glue?'
• 'Pink slime' in your meat? Labels to tell you, USDA says
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The mad cow that was recently discovered through routine testing in California had been euthanized after it became lame and started lying down at a dairy, federal officials revealed Thursday.

How worried should we be about mad cow in US?

The U.S. Department of Agriculture also said the cow was 10 years and seven months old in its update on the fourth case of mad cow disease ever discovered in the U.S.

California mad cow 'just a random mutation'

A spokesman for U.S. Rep. Devin Nunes of California had said Wednesday that the sick cow was 5 years old. It came from a dairy farm in Tulare County, the nation's No. 1 dairy-producing county.

The USDA didn't elaborate on the cow's symptoms other than to say it was "humanely euthanized after it developed lameness and became recumbent."

Routine testing at a transfer facility showed the dead Holstein, which was destined for a rendering plant, had mad cow disease, or bovine spongiform encephalopathy. The results were announced Tuesday.

Animals at high risk for the disease include those with symptoms of neurological disease, "downer" animals at slaughterhouses, animals that die at dairies or cattle ranches for unknown reasons, and cows more than 2 1/2 years old, because BSE occurs in older cows.

U.S. health officials say there is no risk to the food supply. The California cow was never destined for the meat market, and it developed "atypical" BSE from a random mutation, something that scientists know happens occasionally. Somehow, a protein the body normally harbors folds into an abnormal shape called a prion, setting off a chain reaction of misfolds that eventually kills brain cells.

In other countries, BSE's spread through herds was blamed on making cattle feed using recycled meat and bone meal from infected cows, so the U.S. has long banned feed containing such material.

The last two cases found in the U.S. were atypical as well.