Watching Sprocket (our older dog) get old is hard. Lots of staring off into space, slower moment days, etc. We do our best to keep giving him his best life though.
@jerry yeah, Sprocket has made it to 14 (mini schnauzer, so that's not exceptional, but still up there). It's funny how it's harder in some ways than when his brother Thatcher got sick and died at 12, because it's more prolonged, and not something more obvious/treatable.
I just hope he finds a way to make it clear to us when he isn't comfortable anymore so that we can do the right thing by him. Hopefully a long way off still.