The scenario: Pet food sure sounds delicious, with brands offering varieties of brown mush in flavors like "hearty beef stew," "chicken and gravy with rice and spinach," and "grilled seafood," to name a few. The humanization of pet food isn't exactly a surprising trend, either, since we're the ones who pick it out and pay for it at the store. Plus, dogs were domesticated by eating our own table scraps for thousands of years, so it's not too much of a leap to think you could eat their food, too. That might have you thinking: What bad could come of taking a little taste of Fido's dinner?
The basics: Dog and cat food can contain meat from the same farms that produced the chicken and beef on your dinner plate. A perfect cut of New York strip steak is hardly going to wind up in dog food, which is more likely to be made of muscle scraps and offal. But if you don't have a problem with nose-to-tail cuisine, then there's probably nothing objectionable in pet food.
"I'm not saying it's true across the board, but some of the standards in pet food plants are way beyond what I've seen in manufacturing plants that make food for humans," says Kathryn Michel, a board-certified veterinary nutritionist who teaches at the University of Pennsylvania. But even though pet food is held to certain cleanliness and safety standards, they're not the same standards that apply to your grocery counter steaks or Cheerios. Ultimately, that means you probably won't have much legal recourse if eating it makes you sick.
Legally speaking, most pet foods are "not fit for human consumption." While pet foods sold in the United States are monitored by the Food and Drug Administration, the bulk of regulatory work is handled by the individual states. The states generally follow the guidelines set by the Association of American Feed Control Officials, an umbrella organization of all the governmental regulatory bodies.
What's the worst that could happen: If a bag or box of dry pet food gets torn and, say, left in a dirty corner under your kitchen sink, it can easily pick up E. coli or other harmful pathogens, so you wouldn't want to eat that. (Though really you shouldn't be feeding your pets out of torn bags either.) For that reason, it's smart to wash your hands both before and after handling pet food—just like when you cook for yourself. "We don't have as good cleaning habits around pet food as we do our own food," says Beth Ann Ditkoff, a biology lecturer at Sarah Lawrence College and the author of Why Don't Your Eyelashes Grow?
Canned pet food, on the other hand, is supposed to be sterile thanks to the canning process. From time to time, those cans become contaminated during manufacturing. One of the biggest cases was back in 2007, when cat, dog, and ferret food across more than 150 different brands had to be recalled. A Chinese exporter of wheat gluten and rice protein tried to cheat tests of protein content in their product by adding melamine, a type of plastic more commonly found in dinner plates. The poisoning ultimately caused 14 pet deaths in the United States. That kind of fraud is no more legal in China than it is in the West, of course. Just a year later, baby formula in China was found to have the same melamine contamination, making nearly 300,000 infants sick and leading to a dozen deaths. Two company executives found responsible were sentenced to death and executed under Chinese law.
The point is, you're far more likely to bite into contaminated people food, but it is possible to be extraordinarily unlucky and have your one experiment with non-human food result in a salmonella- or listeria-contaminated dog-food meal.
What will probably happen: You'll consume enough meat and vegetables—in probably one of their least appetizing forms—to make a small meal. "There's nothing indigestible in pet food," Michel says. Dogs and cats both require a higher proportion of protein in their diets than people do. Cat food in particular tends to be particularly low on carbohydrates, although some brands include dietary fiber. If you tried to actually live off pet food indefinitely, however, you run the risk of malnourishment in the long term. "Dogs and cats don't need vitamin C in their diet because they make their own," Michel says. As a result, pet food doesn't always contain the vitamin C that humans need. Eat nothing but pet food over a long period, and you might get scurvy.
The upshot: If you really need to win a bet or survive for a few days when food is scarce, then you can pop open a can of dog or cat food without fear. But just like any other food product, you should always wash your hands after handling it, and store it in a clean, airtight container.