"Teacup Yorkies" belong to the Yorkshire Terrier family. The "teacup" classification is not recognized by the American Kennel Club (AKC). "Teacup" is not a breed name -- it is a marketing term coined by breeders to market dogs to consumers.
Problems with "Teacup" Yorkies
According to the Yorkshire Terrier Club of America, responsible breeders don't specifically set out to breed "teacups." Yorkies that are smaller than four pounds are too small to be healthy. They are susceptible to health problems, including birth defects, chronic diarrhea and vomiting, hypoglycemia, and injury (because they are so small they can be easily kicked, stepped on, or attacked by other animals).
Toy vs. Teacup
Yorkies are small dogs. The standard size is four to seven pounds, so they are considered a "toy" breed by the AKC. All Yorkies are "toys." Although AKC doesn't recognize "teacups," that's what some people call Yorkies that are smaller than four pounds.
Yorkies and Kids
There are breeders who don't recommend Yorkies for families with children because they are so small that even well-meaning children can hurt them.
Yorkies are little, but loud. Sometimes they like to pick fights with other animals. They're prone to allergies. They travel well and easily adapt to new situations. Their long coats require frequent brushing.
Bring a Yorkie Home
If having an AKC registered Yorkie is important to you, locate a Yorkie breeder through the AKC website. If having an AKC registered dog is less important to you, you can also adopt from Yorkie rescue organizations, or from a local animal shelter.