The rarest dog in the world is a Six-Toed Lundehund . There are only 1500 hundred in the world and only 250 of those are in the US. The rarety of the breed is due to near extinction when distemper hit ( around World War II) struck Værøy and the surrounding islands. In 1963, the population was further decimated by another outbreak of distemper. This time, only six dogs survived, one on Værøy and five in southern Norway, The latter five were from the same mother. This created a population bottleneck.
These rather cool looking doggies do indeed have six toes, are quite flexible (able to turn their heads 180 degrees)and able to lay completely flat with all four legs out the sides. The Lundehund is originally from the remote islands of arctic Norway, and the name means “puffin dog.” They were indeed used to hunt Puffins and to aid in this endeavor they were breed with 6 toes that each has muscle and skeletal structure, used for climbing rock crevices. There are only 1500 hundred in the world and only 250 of those are in the US.
The Lundehund are small dogs about the size of the spitz breeds. They are about 12 to 16 inches tall and weigh around 13 to 15 pounds. These doggies are happy and active but they do come with an genetic intestinal problem where they do not digest nutrients from the food they eat. the literally starve to death even though well feed. Not all Lundehunds have this problem but they all have the genetics for it. (Keep in mind that many purebred dogs have something that can go wrong with it genetically and the Lundehund is no different. ) All in all I think they are cool dogs and would not mind meeting one in person.