Miles is young and evidently been a tripawd since puppyhood (probably deformity) and very fit, trim, and energetic.  He runs like a maniac around the pasture, my Mom's jack russell cross can barely keep up.  His thigh muscles are like a greyhound.  I swear he could do agility.  He loves to have a purpose, like a working breed, and is so happy to come accompany me for chores on the farm.  I think he'd like to carry a bottle of water and a sweater, probably weighing less than an extra pound or two.  We don't go far on walks and sometimes I grab his handle and lift while he hops alongside, taking a lot of weight off whether he likes it or not.

I have Miles on glucosamine/condroitin preventatively.  I don't know if it helps prolong joints, but I do it.  The vet says that activity is good for preventing arthritis (or slowing it's progress actually) as they age.  I worry that he'll twist a foot running at liberty in the pasture, but I can't stop him from doing that.  When we go for a dog walk, he's on a leash and can't go faster than I can walk, I think that is really good for keeping his muscles strong to support his body on 3 legs.  🙂

I do appreciate your commenting though.  I would NEVER have considered such a thing with Raven, he was older and hopping was not easy because he was a cancer survivor and the muscle development was not there.  I hope that people see your post and do consider what you said.  

Dawn