There are hairless dog breeds, most of which have hair on the head, tail and sometimes feet to one extent or the other. There are coated dogs that carry the hairless gene but then there is the Chongqing Dog with its sparse coat. Before going further let me state the December 2018 China Kennel Union (CKU) Breed Standard states “Hair: Short and very harsh without any undercoat” but let’s dig into this a little further…
So What’s with the “Sparse coat” of the Chongqing Dog?
There are hairless dog breeds, most of which have hair on the head, tail and sometimes feet to one extent or the other. There are coated dogs that carry the hairless gene but then there is the Chongqing Dog with its sparse coat. Before going further let me state the December 2018 China Kennel Union (CKU) Breed Standard states “Hair: Short and very harsh without any undercoat” but let’s dig into this a little further…
There are actually a variety of coat types within this breed… fully coated (likely from hybridization) ; very sparsely coated with velvety, vellus-like hair all over; a coarse, sparse coat which is near hairless starting at the top of the head moving down the spine and extending to the tip of it’s signature bamboo tail with a fuller, coarse yet still very sparse coat over the remaining body. Finally, ever-so-often, a totally hairless pup or two is born within a litter with coated litter mates.
Why so many coat types?
A more recent history of hairless dogs shows both dominant and recessive genes are responsible for hairlessness. The dominant FOXI3 autosomal gene like those present in the Chinese Crested and Xoloitzcuintle (see note 1 for a more complete list of breeds) cause both hair and teeth malformation in the embryonic stage subsequently causing hairlessness and poor dentition in these breeds.
A separate, recessive gene known as the S3KG gene is responsible for the hairlessness in the American Hairless Terrier and some Scottish Deerhounds. The mutated gene does not affect the canine teeth of these dogs. Pups with this mutated gene are born with fuzzy, cotton-like hair which begins to disappear. Starting at 3 weeks of age, this hair begins to diminish starting from the top of the head, working its way down the spine, to the tail and finally down the sides of the body, legs and feet. The American Hairless Terrier is, to date, the only truly hairless breed except for eyebrows, whiskers and an almost invisible, very soft, vellus covering. Anything sounding familiar yet?
Anyone having the pleasure of meeting a Chongqing Dog will sooner or later notice lovely pearly white teeth. A closer inspection will reveal a full set of canine teeth. This rules out the dominant FOXI3 gene which negatively affects dentition. Hmm, that leaves us with the recessive S3KG gene but these dogs are completely naked while the Chongqing Dog is coated albeit sparsely. Genetisists certainly have their work cut out for them. My working theory is this sparse Chongqing Dog coat is affected by a recessive, non-lethal gene mutation. Perhaps the mutation is yet to be discovered? Perhaps it is the same S3KG gene but less affected, less stable or otherwise somehow altered? Further DNA analysis of this hearty breed and future DNA discoveries will one day help us to understand the very unique coat of this beloved, native Chinese breed.
Note 1: hairless dogs with dominate FOXI3 autosomal gene include the Chinese Crested, Xoloitzcuintle, Peruvian Inca Orchid (aka Peruvian Hairless Dog), the Abyssinian Sand Terrier (aka African Hairless Dog), Ecuadorian Hairless Dog, Argentine Pila Dog, the Bolivian Hairless Dog (aka Hairless Khala).
– authored by © Alaina Amason,
owner, LoneStar Chongqing Dogs
West Texas, USA
July 4, 2019
