Dogs have a big environmental foot-print!

"we should put as much thought into choosing a pet as we do into buying a car. "If a lifestyle choice uses more than 1 per cent of your energy footprint, then it is worthwhile reflecting on that choice and seeing what you can do about it," he says. "Pets definitely deserve attention: by my estimates, the energy footprint of a cat is about 2 per cent of the average British person's energy footprint - and it's bigger for most dogs."

— from http://www.newscientist.com/article/mg20427311.600-how-green-is-your-pet.html?page=1