Although a Shetland Sheepdog resembles a small Collie, it is not a “Miniature Collie”. The term “Miniature Collie” implies that the Sheltie is a bred down version of the Collie, which it is not. The early Shetland Sheepdogs came from a small herding dog, called the “Toonie Collie” or “Toonie dog”.
At a quick glance, the two breeds are strikingly alike, if you do not take the size difference into account. And they should look alike. The early Shetland Sheepdogs were crossbred with Collies for “refinement” of the little herding dog from the toons of the Shetland Islands. Even so, the amount of Collie in the Shetland Sheepdog is small. The two breeds developed independently of one another, in Scotland and on the Shetland Islands, and there are differences in history, appearance, size, and character.
If you come across someone who is claiming to have “Mini-Shelties”, all they are doing is breeding under-sized Shelties. Often these people will claim that these dogs are rare and worth more money…do not believe it! These dogs are worth no more than any other pet-quality Sheltie. If you would like a small Sheltie, you are better off just looking for one from a good breeder… there is often a range of different size Shelties produced within a litter.
Someone who is claiming to have “Miniature Shelties” or “Miniature Collies” either does not truly know anything about what a Sheltie or Collie is, or is purposely deceiving you. Regardless, this is not a breeder from which you should be buying a puppy.