How about a doggie treadmill?
For about 480 bucks you can get your furry buddy DogPacer's Minipacer treadmill.
It's made for pooches under 55 pounds.
The original DogPacer handles canines up to 179 pounds and sells for about $500.
Of course, you could also walk Fido in the park.
The Sharper Image Pet-O-Meter Pet Pedometer will tell you who far you've gone and how many calories the human partner has burned.