Willy runs away

This is a sweet children's book about a little street colored dog named Willy who runs away from home. He soon realizes that he is lost, but can't find his way home. He looks in all the places he's been with his people, but as it's nighttime, they are not there. Willy's family, meanwhile, is out looking for him in their car. The children cry as they drive through lonely streets, while Willy wanders aimlessly, his head hanging. Finally, the family and Willy are reunited and all is well. This was one of my favorite books as a child, and the simple yet evocative drawings still move me.