Toy dog term teacup dog, thus the toy/teacup boundary remains fuzzy. The standard size for a toy dog ranges from 4 to 7 pounds; anything smaller than the standard size of a toy dog may be a runt of a litter. No official size defines a teacup dog, but unofficially a teacup dog is considered to be a dog that is 17 inches or less and weighs 4 lbs or less at the age of 12 months. There are no specific teacup dog breeds, but popular types for breeding teacup dogs include: Shih Tzu, Chihuahua, Yorkshire Terrier, Poodle, Pug, Maltese, Pomeranian, and
Dog anatomy "star" of white fur on their chest or undersides. A study found that the genetic basis that explains coat colors in horse coats and cat coats did not apply to dog coats. The project took samples from 38 different breeds to find the gene (a beta defensin gene) responsible for dog coat color. One version produces yellow dogs and a mutation produces black. All dog coat colors are modifications of black or yellow. For example, the white in white miniature schnauzers is a cream color, not albinism (a genotype of e/e at MC1R.) Modern dog breeds exhibit a diverse array