How much does your dog impact the environment? A whole lot, according to sustainable-living gurus Brenda and Robert Vale. In their 2009 book “Time To Eat the Dog,” a medium-size dog’s environmental impact is about double that of an average sport utility vehicle. Dog lovers and environmental analysts immediately dismissed the Vales’ claim, but the controversy bears exploration because it offers a lesson in the meaning of green living and how our pets fit into the equation.
Some people like to lump environmentalism with an interest in organic agriculture, “natural” products and artisanal foods. In fact, green living and “natural” living are entirely separate — and often contradictory — lifestyles, and nowhere is this more evident than in our views on how we feed our dogs.
Take the Vales’ claim. The main reason it was so controversial was because of how the Vales calculated the environmental impact of dog food. They estimated that a medium dog consumes about three ounces of meat and 5.5 ounces of cereal per day, then claimed that it takes approximately two acres of land to produce the calories found in that amount of dog food. They then estimated that an SUV, driven 6,200 milesper year, requires 55.1 gigajoules of energy annually. (This estimate includes the energy required to build the vehicle.) That amount of energy can be produced on only one acre of land.
One of the problems with this calculation is that it assumes the calories that go into dog food are produced for the sole purpose of feeding dogs. In fact, many of those calories are byproducts of human food production. In an environmental sense, they are almost freebies.
Environmental analysts constantly struggle with this concept, which they call allocation. Cows produce lots of different products, such as meat, milk and leather. While dividing up the animal’s environmental impact among those products by weight is convenient, it’s not necessarily a fair reflection of reality.
To put this in the least disgusting way possible, there are many parts of a chicken, cow or sheep that you probably don’t wish to eat. Until laboratory-grown meat makes a gigantic step forward, we can’t manufacture palatable beef without also producing ligaments, tendons, bones and offal. A good portion of those extras end up in animal food.
Under these circumstances, it probably doesn’t make sense to assign a cow’s greenhouse gases to dog food on a pound-for-pound equivalence with human food. Dog food is a byproduct of livestock production, not the purpose. There’s no scientific or objective way to allocate the environmental impacts, though. Even the experts differ in their approaches. Brenda and Robert Vale’s approach isn’t necessarily wrong, it’s just a little bit misleading.
One thing is indisputable, though: As long as we produce animals for human food and refuse to eat nontraditional body parts, we have to do something with the byproducts. Many of them are rich in proteins and useful fats, but some require processing before they can be eaten. Feeding these parts to companion animals is a good idea from an environmental perspective.
This is where your environmental values may diverge from your instincts for wholesome, “natural” living. Many humans not only turn up their noses at animal byproducts, they also decline to feed such things to their pets.
In 2007, for example, the environmental issues Web site Tree Hugger published a green pets guide and advised readers to “swap out the junk food.” The article described most commercial pet foods as made of animal byproducts that few humans would touch and backed organic and natural pet foods as better alternatives. Many up-market brands brag about the absence of byproducts in their offerings. Royal Canin last year announced a dog food made largely from chicken feathers, and the company found itself mocked by skittish dog owners who were disgusted by the idea.
I understand these reactions. We have come to think of our dogs as family members, and in many ways that’s a great thing. It’s important to remember, however, that dogs are biologically not the same as humans. Just because you wouldn’t feed hydrolyzed feathers to a child doesn’t mean it’s cruel to feed them to a dog. A dog can live a long and healthy life on meat byproducts.
Consider the evolutionary history. Dogs exist to eat the things we don’t want. Your dog’s ancient ancestor was a docile wolf that prowled around the outside of human encampments, waiting for humans to dispose of unwanted nutrients such as gristle, ligaments and even feces. Given enough time, your dog would eat your dead body. These creatures are not picky eaters. They have even diverged genetically from their wolf ancestors in ways that make them better at digesting scraps. Erik Axelsson, a genomics expert at the Sweden’s Uppsala University, told the BBC that “the dog evolved on the waste dump.”
Our dogs are doing us a favor by eating the unwanted byproducts of our own food system. If we deny ourselves this benefit, we will have to raise cattle, sheep and pigs for the sole purpose of feeding them to dogs. That would make dogs into a luxury item that would be difficult to justify from an environmental perspective.
Put simply, if we feed choice cuts of meat to dogs, then the Vales’ calculation is pretty close to accurate. Your dog’s carbon footprint would become uncomfortably similar to that of a sport utility vehicle. Don’t make Fido into an unnecessary burden on the planet.