Aw, Phred! This certainly stinks! Hang in there!
You couldn't have done more for him if you tried. He may still show up. Lots of people know you were looking for his family and may give you a call. He could very well show up again on his own after he gets his adventure over.

Sometimes we are only meant to lend a helping paw er hand, for a little while on anothers journey through life, be they human or nonhuman. Sort of like a pit stop on the road of life.

Maybe you were meant to help him overcome his barking problem so he can find his forever home.

Prayers on the way for BigKid and you too!