The barkless dog:

Bob was a special dog. Bob did not bark. When Lucas, his owner, walked him, he could hear all kinds of barking, except from Bob. The boy soon realized something was wrong. Why was Bob the only dog who did not bark? In this book, of rare empathy and awareness, the authors strive to show children - and adults - it is important to speak up, demonstrate how they feel, and express what upsets them. In a lighthearted way, the authors aspire to encourage children not to be silent in any kind of situation.