Natural bobtail

A natural bobtail is an animal's tail which due to a mutated gene grows unusually short or is missing completely. The genes for the shortened tail may be dominant or recessive.

Due to legislation restricting or preventing docking, natural bobtails are growing in importance in the hobby of dog fancying for some traditionally docked breeds. For example, one Boxer breeder and geneticist in England has successfully petitioned the Kennel Club for permission to cross Corgis into his lines and then backcross to Boxers, introducing the gene into his lines. This would have been unheard of in decades past. A number of these bobtail Boxers have been successfully exported to various countries around the world.

A mutation in a gene called the T-box transcription factor T gene (C189G) accounts for natural bobtails in 17 of 23 dog breeds studied, but not in another 6 dog breeds, for which the genetic mechanism is yet to be determined.

Natural bobtail dog breeds with C189G mutation:

Natural bobtail dog breeds without C189G mutation:

Dog breeds into which the C189G mutation has been introduced by cross-breeding:

Dog breeds where natural bobtails have not yet been tested for C189G mutation:

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Wikipedia