Technically, there is no such thing as a teacup cat breed, as most miniature cats are simply very small individuals of smaller breeds. The smallest recognized breed of cat is the Singapura, which was brought to America in the 1970s. Other small breeds include the Munchkin, Minskin, Dwelf, Napoleon, Bambino, Kinkalow, Lambkin and Genetta.
Miniature cats are usually half the size of normal cats of particular varieties. Some of the smaller breeds of cats are simply bred among each other to make another small breed. For instance, most of the smaller breeds started by breeding a Munchkin with other varieties, such as Persians, Sphinxes and Selkirk Rexes. The Munchkin is a short-legged cat known since World War II, although the International Cat Association did not recognize the breed until 1994. Munchkins have very short legs because of a genetic mutation that kept going with each generation.
Singapura cats develop slowly into adults, as kittens do not reach adulthood until they are 15 to 24 months old. Fully grown Singapura cats weigh between 5 to 8 pounds and have small feet, a brown coat and large ears that resemble an Abyssinian.
Many breeds based upon cross-breeding Munchkins are considered dwarf breeds because the cats' legs are shorter than usual but everything else is normal. For a particular cat to be considered a teacup or miniature size, the cat's proportions are all normal except the overall size is smaller than that of a regular specimen.