A couple’s relationship becomes intrinsically linked with their troublesome dog.
When the dog dies (sorry, spoiler), all the heartache of his grieving family could be solved at a stroke by creating a clone of him.
You could have an endless supply of Marleys in fact, thus preventing any pet-based upset ever again.
And if the Grogans can't face owning another dog, we've got a sheep they can buy instead.
Her name's Dolly and she's an immortal.