A blogger posted this pic, saying he met this hiker and her pup on the trail. The dog is paralyzed from the waist down, but still gets to get out and hike with her owner because she brings her along in this backpack fashioned for her!
Even if you don't think your dog is right for long hikes, that's fine. There's always a way to help get them outdoors more and help get them to be able to enjoy their experience outside! Just figure out what's right for your dog and go from there.