Very few people stop to consider the environmental impact of their family pet. In the United States alone, there are over 77 million owned dogs, and over 93 million owned cats. These numbers do not include feral animals or animals in shelters. All of these animals are, by their nature, meat eaters. That’s where a good part of the problem comes from.
The average medium-size dog eats approximately 160 kg of meat and 95 kg of cereals a year. According to the book “Time to Eat the Dog: The Real Guide to Sustainable Living” by New Zealanders Robert and Brenda Vale, this gives the family dog the environmental footprint of about 0.84 hectares, or the same as an SUV traveling over 10,000 km a year. Cats fare a little better, with an ecological footprint of 0.15 hectare, which is about the same as a compact car driven for a year.
These numbers do not take into account the amount of waste produced by pets, which in the United States is estimated at nearly 10 million tons per year. Much of this ends up in landfills or flushed down toilets. While municipal waste treatment systems can handle dog feces, they cannot handle the toxoplasmosis parasite in cat feces, which can make people sick and can be fatal to sea otters.
Add to that the damage pets deal to the surrounding wildlife, in particular by cats to birds, and pets are beginning to look like an environmental drain. Cats can kill up to 25 birds, rodents and frogs every day, while dogs can significantly lower biodiversity along the paths they walk.
There is another side to this story, though. Some municipalities, like San Francisco, are looking into the idea of using pet feces to generate bio fuel. While pets may eat a great deal of meat, the above statistics do not take into account the fact that the meat eaten by most dogs and cats is waste meat, which is unsuitable for human consumption, and would otherwise end up in a landfill. It is also possible to decrease the meat consumption of companion animals, and switch them over to animal proteins.
Of course, there is another side to pet ownership. People derive a great many intangible benefits from their pets. Owning a dog is better for high blood pressure than many types of medication, and the ownership of any animal is good for lowering stress and reducing loneliness and depression, especially in the elderly.
Having said that, though, as the world’s population rises, and meat consumption drops, the economic and ecological cost of pet ownership will continue to increase. There may come a time when it becomes unacceptable to own a pet that doesn’t have another purpose. As that time approaches, we will likely see the development of robotic surrogates that will stand in for pets. Until then, people will continue to care for their pets, and look for ways to lower their environmental impact.
