The 14-week-old pup called Disney is too small to hang around with other dogs and now thinks she is a kitten.
The pocket-sized pooch, which was a part of a litter of three born in January, has not grown since she was eight-weeks-old.
Disney weighs just 405 grammes - lighter than a bag of sugar, Mirror reported.
Owner, Natalie Vanes, has to keep Disney away from her three other dogs at her home in the West Midlands, so that they do not mistake her for a toy.
If Disney continues to grow at the same rate, the miniature mutt is on course to break the Guinness World Record for the smallest dog, the report said.
