Which is the only dog that cannot bark?

Could you elaborate on the intriguing mystery surrounding the canine species that is unique in its inability to bark? Is there a specific breed of dog that stands out for this silent trait, or is it a more nuanced characteristic related to a particular condition or genetic anomaly? How does this lack of barking ability affect the dog's social interactions and communication with its human companions? Furthermore, what are the implications of this phenomenon for dog owners and trainers? I'm eager to learn more about this fascinating enigma within the canine world.