how to make a slowly aging dog exercise?

Uh, obviously no one here that suggested ‘walking’ has ever had hip dysplasia! haha If there is any possible way, find a swimming pool or maybe a hot tub – hydrotherapeutic exercising is a great way for her to exercise without putting more strain on her already degenerated and painful joints. She shouldn’t be climbing stairs since it obviously hurts her to do so – hip dysplasia is progressive so if she was diagnosed with radiography at two or so (or younger) and you haven’t seen xrays of her recently, you might be horrified to see how degenerated that joint can become – even good joints get painful on dogs (and people) as they age but bad ones get awful! They also put strains on other joints that will end up degenerating as well (elbows, patellas, etc.). She is hurting – see about talking with your vet about the situation – if the joints are really bad, they might require surgical intervention – talk with the vet too about possible analgesics and/or anti-inflammatory meds that could help relieve some of her pain. I know one GSD owner whose dog had HD and she also had him on glucosamine chondroiton and it seemed to help a whole lot – not sure of the dose but again, discussing this with your vet might be helpful for dosing and such. Good luck and hope you find or get a pool of some sort for her – it takes the weight off the joints and not only is good exercise but actually helps with pain relief.