Nestlé, the largest food company on the planet, announced today that it's recalling some of the beef pasta meals it sells in Spain and Italy. The reason? The "beef" contains horse DNA. And Nestlé's not the only company. Nearly all of the U.K.'s biggest supermarkets and many of their suppliers have been forced to remove horse meat fraudulently labeled as beef from the shelves as more and more companies are implicated in the widening scandal. Where's the horse meat coming from? How is it getting into the beef? Has the United States' supply been compromised? We've got the answers.

What is the horse meat scandal?

A number of frozen meals and food products at supermarkets across Europe have been found to contain high levels of horse DNA—in some cases, as much as 100 percent of the meat was horse—indicating that the meat being marketed as "beef"... isn't.

Gross. So people who thought they were eating beef were eating horse?

Yes. Nearly all of the U.K.'s biggest supermarket chains have had to remove products from the shelves, and the head of the Food Standards Agency there says we'll never know how many ate horse without being aware of it.

Are the people who ate horse going to be okay?

They're going to turn... into... horses! No, they'll be fine. People across Europe eat horse, on purpose, and love it; celebrity chef Gordon Ramsay serves it at his restaurants in the U.K. Provided the horse is properly raised and slaughtered, there aren't any health risks to eating its meat. In this case, there is a minor health risk from the equine anti-inflammatory phenylbutazone, or "bute," which in extremely high doses can cause certain blood diseases—but this is an issue caused and exacerbated by the much larger and more disturbing scandal of fraudulently and misleadingly labeled meat with unclear provenance.

Unclear provenance? How did the horse meat get into the food?

No one seems to know entirely. Yet. In Ireland and the U.K., the fraudulently-labeled beef sold by supermarket chain Tesco appears to have entered the supply chain through beef processing multinational ABP, two subsidiaries of which produced the contaminated meat. ABP claims to have traced the horse meat through the Netherlands to Poland; Polish authorities strenuously deny that their slaughterhouses are responsible, and have undertaken tests and found no horse DNA in samples.

An entirely different horse meat supply chain emerged in France, through another food processing company, Comigel, which was tasked with supplying a beef lasagna dish to the frozen food company Findus; Comigel—through a Luxembourgish subsidiary—ordered beef from a Spanish company, which ordered it from a Cypriot trader, who outsourced the job to a Dutch trader—a guy who'd already been convicted of selling horse meat—who (deep breath) finally placed the order to a Romanian slaughterhouse, where the horse meat originated. Sent back to Luxembourg through Spain, the horse meat was processed into the frozen lasagna dishes, ending up on shelves in the U.K., France and Sweden. No one knows how far up the chain the coverup went; the Dutch trader, Jan Fasen, has accused Comigel and its Spanish suppliers of being fully aware that they were passing off horse meat as beef.

Two different supply chains? How widespread is this?

It's hard to tell. Tens of millions of pounds of horse meat is processed and sold around Europe every year; beef is getting more and more expensive, and supply lines less and less direct; and with rolled-back and under-funded food safety operations in the U.K. and elsewhere, it's harder to detect when meat is adulterated.

So how did anyone find out about it?

Last November, Irish food safety authorities tested a range of supermarket beef products and found most of them to have some percentage of pork and horse DNA. The Irish regulators made their U.K. equivalents aware (Ireland says in November; the U.K. says in January), and the U.K. Food Standards Agency did its own testing—confirming the Irish discovery of the Tesco/ABP network and uncovering the Findus/Comigel supply chain.

Wait—there was pork in the "beef," too?

Yes.

So why isn't it a pork-and-horse-meat scandal?

Good question! One, because the general cultural squeamishness about eating horse on the part of the U.K. and Ireland (at least compared to continental Europe) means that unknowingly eating horse is regarded as totally grosser and worse than unknowingly eating pork; and two, because pork is unlikely to contain bute. (May I suggest, though, that if you are deeply bothered by eating mislabeled horse meat but not mislabeled pig meat, you should reconsider your attitude toward food.)

Have I eaten mislabeled horse meat?

If you live in Europe, well: maybe? Especially if you're getting a lot of your food from the pre-prepared frozen meal section of the supermarket. If you live in the U.S., though, probably not.

"Probably"?

Reassuringly, none of the companies involved in the European scandal—so far—export beef to the U.S. And since Americans don't love horse meat at the same level that—say—Italians do, and since there are currently no legal horse abattoirs in the U.S., there's just less horse meat available to contaminate the supply of beef.

There aren't any legal horse slaughterhouses in the U.S.?

No—in fact, slaughtering horses for meat was rendered de facto illegal between 2007 and 2011, when tax dollars were forbidden from going toward the mandatory inspections. (Some states, like California and New Jersey, have their own statewide horse-slaughter bans.) Since that ban was lifted no abattoirs have opened, putting horse meat in a sort of legal grey area, subject to conflicting and changing regulations. As of the latest information we've been able to uncover, any horse meat to be sold or served to the public must have been inspected by the USDA at the point of slaughter; this effectively outlaws it, as imported meat hasn't been inspected, and there are no domestic abattoirs subject to USDA regulation.

That being said, horses are still exported to Canada, Mexico and Europe for slaughter. In fact, there's been speculation that some of the horses that were ultimately slaughtered in Romania and Poland and ended up in freezers across England may have come from the U.S. According to one survey, something like 138,000 horses were exported from this country in 2011 to be slaughtered for their meat—many of them still containing bute in their bloodstreams.

Wouldn't I be able to taste the difference? What does horse taste like, anyway?

It's leaner than beef, softer, and a bit sweet and gamey. Think something between venison and beef. If you were told it was beef, especially some kind of cheap beef drenched in tomato sauce, you probably wouldn't notice.

How's it usually cooked?

In Europe, it's most often cured and put on sandwiches or made into sausages and salami, though you can also find it cooked up like a steak or made into a stew. In Japan, it's frequently served raw.

Let's say I want to try horse meat. Where can I find it?

The last restaurant we know of that tried to sell horse meat here in the states was the Queens restaurant M. Wells, which planned on serving a horse meat tartare with Canadian meat before it found itself subject to wide public outcry, and a last-minute change to U.S.D.A. regulations. For now, if you want to eat horse, your best bet is to hop over the border to Quebec, where it's still relatively widely consumed.