Running dogs come in all shapes and sizes. I trail run with a guy that brings a Pomeranian. This little puff ball has gone as far as 14 miles and appears to be fine, go figure. From my experience, the long steady pace that is found while running on the roads appears to be a lot harder on dogs than trail running with occasional stops and a bit slower pace. If you can get then off leash, that they do even better. Take care of there feet, pavement will sand their paws right down and trails are known for sharps.
