I lost my old sweetie, Mickey a couple years ago to old age and yes, it was hard to watch her age. As her hearing and sight diminished, she stayed close to me on walks instead of being 20 ft. ahead of me. I had to take it as it was...this is how she was then and enjoy that she could still walk and smell and hear (sort of) everything around her. I guess I had to focus on how she was at that time of her life and not so much on that she was older and I would lose her in the somewhat near future. We still had wonderful walks and playtimes but just different than before. I know you feel that pain already, just try not to focus on it completely. You can't ignore that they're getting older of course but enjoy and make it the "new normal" with the changes.