A very short (less than three pages) short story about a boy living on the moon and his robot dog, Robutt. The robotic playmate theme is much like Robbie, a longer short story written in 1940. A Boy's Best Friend deals with a very interesting issue - whether or not it matters that a robot dog can feel love or not, as long as it acts as though it does.
This short story was written by Isaac Asimov in 1975 for Boys' Life, and has only appeared in one short story collection, The Complete Robot.