Instructions
Find Mariokarts while on walks with your pet. The karts can be found hidden behind bushes next to the sidewalk.
Drive the cart around the border of a room to exercise your pet. Your pet will run around behind the kart until it is exercised and tired. Avoid bumping into your pet or it will dislike the kart and not want to play with it anymore.
Switch the view of a room from aerial to right behind the cart while driving by pressing the R and L buttons simultaneously. This can make driving a lot more fun.