I'm new here, so background story first:

I adopted Stella, a german shepherd mix, last June 2015. She was six months old when I adopted her; was hit by a car/had her back leg amputated when she was three months old. When I first brought her home, her endurance was awful. Like, three blocks and DONE. Now it's been almost a year since I've had her; she's about a year and a half old with puppy energy. I wanted an active dog, and was determined to make her one. She goes to the dog park daily, can run as fast as all the other dogs. Living in Colorado, I take her for hikes (no more than 3 miles and no stairs). Last week I took her for a run and we wound up doing 3 miles.

My question is, am I pushing her too much? We don't just do "normal 15 minute walks". We either run together, play tug of war or she's at the dog park keeping up with the other dogs. She seems just as fatigued as a normal dog would after a 3 miles run; she'll be tired and nap for an hour or two and then wake up and want to do it again. I just want to make sure I'm not going cause any issues down the line as she gets older, or risk injuring her by pushing her the way I do. I basically treat her as if she's an adventurous, fit, high endurance dog - because, well, she loves it and can keep up. I just know that as a tripawd she probably has more limitation. I ask now because as summer approaches, and with the endurance she has built up now, I'd love to take her on more mountain hikes.