What makes a rare dog breed rare? For a start, many dog breeds considered rare by dog registries don’t exactly look like a dog. For instance, you could mistake the Bedlington terrier for a lamb or the Komondor for a mop. The Norwegian Lungehund that originated on the Norwegian coast during the Ice Age has six toes on its front paws.
Attributes that make a few dog breeds rarest of the rare:-
Peculiar barking (the bark of the New Guinea Singing Dog sound as if the canine is trying to vocalize)
Vegetarian (yes there is a dog breed that only feed on milk and bread-the Kashmiri Sheepdog variously referred to as Kashmiri Mastiff or Himalayan sheepdog)
Towering height (the Caucasian Ovcharka also called the Caucasian Mountain Dog and Russian Shepherd Dog is larger than most dog breeds)