Exterior and morphology of dogs

A "natural bobtail" is caused by a mutation in the "T" gene and visually appears as a shortened tail. Has an autosomal dominant mode of inheritance, that is, even one copy of the mutant gene is enough for the manifestation of the trait.
The length of the shortened tail may vary depending on other as yet unclear genetic factors, in some cases it may be a half-shortened tail, in some it is almost completely absent.
Based on scientific evidence, the presence of two mutant alleys is lethal, such dogs die.

The test is not performed on the following breeds: Bulldog, Boston Terrier, King Charles Spaniel, Miniature Schnauzer, Parson Russell Terrier, Rottweiler, French Bulldog.