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If the package of dog food that you regularly purchase for your dog had a picture of a dead dog on the front accompanied by the words, “Fortified with 100 percent natural dog meat!” would you still buy it? Probably not. And yet this might very well be what you are scanning at the grocery store checkout and scooping into your dog’s bowl.

Dog food is made from many strange things, only a few of which are evident in the list of ingredients. The packaging tends to depict fat, healthy chickens; vegetables that look like they ought to win a ribbon at the county fair; and either thick, juicy steaks or sedate-looking cows. But at around $15 for a 15-pound bag of dry food, nobody is spending enough money to turn a T-bone into dog food. The stuff that ends up in dog food is material that can’t be sold as food for humans. We have different standards for what our animals eat from what we would put in our own mouths, but where should we draw the line?

Under Food and Drug Administration regulations, only about 50 percent of a cow can be sold for human consumption. The hide, bones, digestive system and it contents, brain, feces, udders, and various other undesirable parts are all left over after a cow is slaughtered and butchered. The stuff that can’t even go into hotdogs gets consolidated and shipped to rendering plants. Slaughterhouses that handle pigs and chickens also send their leftovers to rendering plants. So do many other facilities that find themselves with large volumes of otherwise unusable dead animal parts, including animal shelters and veterinary clinics that euthanize a lot of animals.




A rendering plant has a huge grinder that is filled up with whatever comes in. Some rendering plants are pickier than others, and some process ingredients in different batches to comply with state or local laws. But on the whole, most tend to dump in whatever they receive and start the grinder when it is full: parts from slaughterhouses, whole carcasses of diseased animals, cats and dogs from shelters, zoo animals, road kill and expired meat from grocery store shelves (tossed in fully packaged, complete with plastic wrap and Styrofoam).

This material is slowly pulverized into one big blend of dead stuff and meat packaging. It is then transferred into a vat where it is heated for hours to between 220–270 degrees F. At such high temperatures, the fat and grease float to the top along with any fat-soluble compounds or solids that get mixed up with them. Most viruses and bacteria are killed. The fat can then be skimmed off, packaged, and renamed. Most of this material is called “meat and bone meal.” It can be used in livestock feed, pet food, or fertilizer. It joins a long list of ingredients that you might prefer not to see in your pet’s food.

There is essentially no federal enforcement of standards for the contents of pet food. FDA technically has authority, but the agency has passed this off to a set of partnerships and nongovernmental organizations that encourage mostly voluntary compliance with the few federal standards. The Association of American Feed Control Officials takes the lead in setting and maintaining standards, but it conducts no testing of food and has no enforcement authority. In practical terms, regulation of the contents of pet food is largely accomplished by those individual states that bother to get involved. Some states, such as Florida and Nevada, have no regulations at all. Others, such as California, require that rendered pets be labeled as “dry rendered tankage” rather than meat and bone meal. However, even California allows rendered pets to be processed and sold out of state for pet food as meat and bone meal. The city of Los Angeles alone sends about 200 tons of dead pets to a rendering plant each month. There is no inspection of pet food or meat and bone meal shipped in from other states.

Many pet food manufacturers, including this site run by a pet food industry group, say that they are not using rendered pets to make a cannibal of your dog. But how would they really know? There is no simple way to look at a shipment of meat and bone meal and tell exactly what species are in the mix. The protein percentage of a load of cats and dogs looks basically the same as a shipment of carcasses from a poultry farm. The rendering industry gets very vague about what is in meat and bone meal, even in otherwise highly technical documents.




The idea of pet dogs and cats being used to feed other dogs and cats is disturbing to us. The mangled road kill, diseased cattle and pigs that died before making it to the slaughterhouse all seem like things that we wouldn’t want anywhere near our pets. But does the ick factor really make it wrong? It is difficult to imagine what else we would do with all of this dead biomass if it wasn’t being rendered, and it seems wasteful to feed high-quality meat to pets who can’t tell the difference. It is, in a sense, a laudable form of recycling.

Perhaps the real problem is with the other things that hitch a ride with the dead cats, dogs, zoo animals, and some of the livestock that were rejected for human consumption. Many of these animals died after being medicated for health problems that contributed to their deaths, and not all drugs are neutralized during the rendering process. Meat and bone meal can contain antibiotics, steroids, and even the sodium pentobarbital used to kill pets at shelters. By definition, a lot of the animals that ended up in the rendering vat had something wrong with them.

This mass of otherwise unwanted death is a measure of the animal suffering caused by human activity. Fifty percent of all chickens hatched out for the egg business are unneeded roosters that are discarded. Roughly 75 percent of all cats in shelters are euthanized. Because they were unprofitable, because they were inconvenient, because we made too many of them, they were killed.

The more that I learned about the pet-food business while writing this article, the less significant the cannibalism aspect seemed to me. My initial outrage at feeding dogs to dogs gave way to outrage at dogs being overproduced and dumped in shelters to be killed in the first place. One million deer are killed by vehicles each year. Even the plastic and Styrofoam from wasted grocery store meat that nobody even bothers to unpackage before rendering has come to seem a minor harm compared to the sins of a food system that devotes so much arable land to producing meat—in a world where people still starve to death—that we can’t even get around to eating it all before the expiration date hits.

It is easy to get up in arms over something that might affect the health of our pets. Indeed, the same system that doesn’t know whether its main ingredient is chicken beaks or dachshund really cannot guarantee adequate nutrition to the dogs that eat it. But perhaps we ought to be more angry about the parade of unwanted carcasses that fuel our need for a rendering industry in the first place.

Given the existence of a food system that produced this much waste, what else should we be doing with all of this excess animal protein? The alternative would probably be to toss this material in landfills. Turning it into pet food is at least a form of recycling.