Dogs love to smell butts and they even sometimes even eat their own (or other dog's) poops. I have never seen a dog grossed out by something. When I was home in Michigan over the holiday I was walking my dog and she picked up a stick, I went to get the stick out of her mouth and it was a half frozen Squirrel or chipmunk or something. Sick! Dogs have no shame and are down for about anything, except I guess farts. Maybe its because they usually get blamed for farts, or maybe because they have those super sensitive noses, I'm not sure. Here is Urlesque's top youtube videos of dogs reacting to farts.