The Motivation Running Belt from Hurtta is a great choice if you're looking for a multi-purpose bag for running with your dog or dog walking.
The running belt features 3 separate pockets, 2 of which have zips and the third secured with velcro. The pocket with velcro has a removable liner that can be easily removed and washed should you wish to clean after using it to store dog treats.
The waist band is adjustable and the bag also includes a small caribina clip, which can be used to hang keys or spare dog leads.
There is also a pull through feature for easy access to dog poop bags.