The chow chow and the Chinese Shar-Pei both have purple tongues; however, the chow chow is the only dog breed to have a purple tongue with purple gums and lips. In both breeds, the dogs are initially born with pink tongues which fade to purple as they mature. A common misconception is that any dog with any purple pigmentation on its tongue must be crossbred with a chow chow.
Purple spots and coloration on the tongue do not necessarily mean that the dog has chow chow in its lineage. This discoloration is common in over 30 different breeds of dog and is comparable to birth marks or freckles on humans. The chow chow is considered to be one of the more ancient breeds of dog. Through DNA testing, the chow chow has been found to be one of the first breeds that evolved from wolves. The dog was originally found in Mongolia and Siberia, before it spread to China and Tibet where it was primarily used as a temple guard dog. Due to cold regions from which they came, chow chows evolved to have a very thick coat and a large mane. They have a curled tail, straight hind legs and are one of the only dogs to have a blue or gray nose.