on daily walks with your yorkie? I have fenced in yard & so had always exercised mine by playing outside with an occassional walk. But....my vet told me that he is a bit overweight

so I have been walking him every morning & some evenings for added exercise.
I've been just walking through the neighborhood, but my property borders with a federal park that has all kinds of trails. I think he would really enjoy it, but I think once you're on the trail that it is awhile before you come back out onto the road. So, how long do you think they can exercise safely & still have fun??
Thanks!!