I don't have a dog at this time in my life. However I do have fun observing my neighbors dogs as they walk them past my house. (Thankfully we live in a neighborhood with folks who clean up after their dogs.)
This morning as I was riding my recumbent bike in our sun room I was struck by the sight of a somewhat senior gentleman walking his very senior dog. They were mostly ambling along at a snail's pace. I couldn't tell whether the dog wanted to go slower or the man! Each would take a few paces and stop to gaze at their surroundings. Mostly the dog was setting the pace. I think the leash was just for show since I expect the running days for both were past.
I think dog walking in this case is a metaphor for relationships that have lasted a long time. We seniors often have relationships that have endured many companionable years. The pace in those relationships has slowed down over the years. Early on we engage in mad dashes of activity sometimes lasting over days. Connections are tight and sometimes like a leash restraining. Later on we loosen the reins and participate together with less restrictions. And in the later years expectations wane to the point where we sit back and spend more time in contemplation rather than activity. I guess the dog and man in my illustration today have found a comforting pace providing time to stop and "smell the roses'. No need to rush through the necessities of the day,