If you’ve had a dog, you’ve probably wondered what the answer is to this question. Butts are pretty gross, after all. That’s where poop comes out, but then again…dogs love poop. All kinds of poop, but from what I can tell, mostly cat poop. https://www.instagram.com/p/BHXaADYAl1a/ So, why is this a pooch’s preferred method of greeting?...