A Children’s book from the mid-50s to 60s about a small dog who is adopted by a circus. Every night he gets a bone from the cook, who says, “To a good dog, a good bone!” He buries it but can’t find it in the morning, getting more and more upset until one night he stays up and realizes the circus moves during the night. He perks up, realizing that since the circus does a circuit, he’ll have a bone to dig up in every town! I believe the illustrations are charcoal, black and white.
Could be Beano, Circus Dog by Helen Orr Watson. Cover illustration looks charcoal-ish. Here’s a description: This tells of a cast-off mutt who wins a warm home and a well-earned reputation in a circus. Red, the animal feeder, buys Beano and both land in trouble, brought on, for the most part, by Beano’s affection and near-human desire to see his new master get ahead. Beano, a natural show-off, becomes a clown dog in the bareback act and Red, who has been working with the lions, gets a chance to perform with them — and the pretty lion trainer’s daughter.
Little-Or-Nothing from Nottingham, by Marguerite Henry, 1949.