I have to disagree with this article to some extent. I never liked cats and have never owned one, but I have to say that pet owner's on the whole have more of a reason to be eco-friendly than families without pets or kids. Honestly my German Shepherd picks up anything that appears chewable and attempts to ingest it. I also have sugar gliders, and they occasionally get to play outside their cages and root around for anything they can fit in their mouths. And then there's my poodle, my first baby because she doesn't shed and is the most low maintenance of all 4, at least when it comes to cleaning up after them.
Because they are on the ground all the time and chewing and rubbing against everything, I have to be absolutely careful what is in my house. No poisons or toxic cleaners allowed, if my sugar glider found a bug on the ground that had been poisoned, bye bye expensive exotic pet! These creatures are a constant reminder that I need to take care of the planet because I am sharing it with every living thing. And the gliders pretty much only eat fresh fruit and baby food so organic is the only answer, I wouldn't risk their health. My animals make me eat better and use eco-friendly products all around. (Ok not true, recently I got so fed up with the flea problem we developed this year and used a pesticide shampoo on the dogs...gasp! I'm trying to make up for it though!)
So I guess even if pet owners have more of a reason, it doesn't mean they follow it. I think pesticides are my biggest worries with pets because they are so hard to keep pest free without constant grooming. Obviosly with these principles in place, I would be slightly more eco-friendly without more mouths to feed and bodies to bathe.
I still conclude that a pet's footprint is determined by the owner, not by the pet!