This video is incredible. It comes from the Smithsonian channel, which I do not get, but fortunately for us it's also on YouTube. This short video gives some great statistics, and may shed some light on why there is so much dog poop in Paris.
On a related note, we are trying to build the PicturesofDogDooDoo community internationally and are looking for a correspondent in Paris (or anywhere else in the world). It's the "movement" of the future!