A difference of 14 years

There is a difference of 14 years between oldest (Lisa) and youngest (Pluto) dog in our family. Lisa is born in January 1996 and Pluto is born in December 2009.
When we got Pluto some weeks ago we really realised how the years have affected Lisa. She is grey in the face, a bit dimmed in the eyes, not that muscled, ears are standing, slower in the movements, likes to sleep in the sofa etc. Of course we have seen all this, but with another IG in the house it became really obvious.
But despite all this she can invite Pluto to playing. She jumps around with tail high and front low to get him in playing mood. I get all warm inside when looking at her behaving like a young girl. Every day with her is happiness.