My dog is 4 months and 2 weeks. We've been going for walks for the last few weeks (since he got his last shots). What age should he be before he runs with us? I don't want to strain his growing legs. Any advice?
Wait at least a year, maybe 18 months to do any on leash running. Hips development has to be complete or you risk dysplasia. That is a painfull life for a dog and/or thousands in hip replacement surgery. Off leash playing, where the puppy can stop and rest whenever it wants to, short bursts of playing with frequent rests is ok for hips. Time will fly by and you'll be jogging before you know it.
My vet said that on and off running (as in walk a couple min, run a couple min) over varied surfaces and inclines, and maxing out around two miles is fine at any age. So that is what we do. I also have been stopping at a stream and letting him swim/romp in the water.