Best Steps for elderly dog

Another idea, depending on how heavy your dog is and what you can tolerate. There is a harness type thing that goes under their belly and has handles. A neighbor of ours had this after their dog had hip surgery and wasn't supposed to climb. They put it on , lifted the dog out of the camper to the ground and they could leave it on for their potty walk. Came back, lifted the dog up into the camper and then took it off. You might find something like this under medical supplies for pets. A cheap alternative would be a canvas wood carrier.