Addendum

The other reason to take your doggie for a walk is so that it can poop or pee. You can totally tell which one it's going to do, just by the animations. Plus boy and girl dogs have different animations. Man, the animation in this game is great. I finally got myself a second dog, a Shiba named Khan, and the interactions between my two dogs is priceless. But, back on topic: Walk your dogs!

And pick up their poop! Only total fuckwits don't clean up after their dogs.