Bodies are merely the custodians of an indestructible spark of life. The body and the soul mature and grow old together. Old people don't understand the younger generation because they keep entirely different dreams as reality. In time the body becomes a corpse and the spirit moves to the place where souls go to rest, to rejuvenate, before they start a new role in a new body. Shawsong was a pet of mundane as well as famous people. He may have another existence, another role to make observations, somewhere even now.