What is the rarest dog?

As a curious enthusiast of canine breeds, I often find myself pondering the depths of canine rarity. After all, there is an abundance of dogs spanning diverse sizes, colors, and temperaments. But which breed stands as the rarest of them all? Is it a hidden gem from a remote corner of the world, or perhaps a breed that has dwindled in numbers due to changing trends or lack of awareness? The question begs to be answered: Amongst the many varied canine companions we share our lives with, which one reigns supreme as the rarest dog?