No, none of the dog breeds you are about to see are large dogs that have been hit with a shrink ray. These breeds are not solely meant to be miniatures of their larger look-a-likes, they were bred for their own specific purposes and fit those purposes well.
We begin with a breed not commonly seen outside of show rings, the Alaskan Klee Kai. The breed was developed in the 1970's by a woman who accidentally bred her husky with an unknown small dog. She then refined the breed by adding in Schipperke, American Eskimo Dog and Siberian Husky. She carefully bred the dogs, introducing small breeds, to avoid the possibility of introducing dwarfism. These dogs are great companions, but can be a little standoffish around strangers, as a result they make excellent guard dogs. They excel at activities like agility and other obedience courses.
The next dog is the Miniature Pinscher. This breed seems to be a tiny version of a Dobermann, but don't be fooled. These dogs have a long history, appearing in portraits of the wealthy dating back to the 1600's. They were probably bred from a combination of Italian Greyhounds, small German Pinschers and Dachshunds, but their exact origins are unknown. They were bred to be companion dogs, which they can be, but they are also highly energetic. Some say they are the most energetic breed of dog.
The Italian Greyhound is the oldest breed we will talk about. Its origins date back 2,000 years to Greece and Turkey. Due to its ancient origins its breed history is unknown, but as we have seen, it has been the base of other breeds. The dogs, like their larger cousin, are sight hounds that love to run, but they were mainly bred to be companion animals. They make wonderful family pets; they are gentle with children and other pets and have enough energy to play all day.
Cavalier King Charles Spaniels originates in Tudor England, but was fully recognizable by the time of King Charles I reign in the early 1600's. The breed originated from working spaniels and imported small dogs from Asia. The breed's resemblance to the Brittany Spaniel came about in the 1800's. The breed is well suited for its original purpose of being a lap dog to keep court ladies warm (and collect their fleas). It is one of the most popular breeds in England which almost led to its downfall there. As stated in a prior post brachycephalic animals, this condition can cause damage to the animal. In the case of Cavalier King Charles Spaniels the selective breeding for a reduced snout led to brachycephaly that was so severe their brains were being compressed causing massive neural damage, excruciating pain, and seizures.
Please remember that as adorable as these dogs may be, their breeding can lead to health problems. To avoid this either buy a dog from a reputable breeder or ADOPT a mixed breed dog at a shelter- hybrid vigor and all that jazz.