Screw tail is a type of natural short tail that can be found in Bulldogs, French Bulldogs and Boston Terriers. It is different from the natural short tail seen in Pembroke Welsh Corgis because the bones in the short tail usually make a kinked rather than straight shape.
The gene that causes screw tail (the DVL2 gene) does not just change the shape of the tail. It contributes to the brachycephalic skull type that gives the screw tail dog breeds extremely short noses. Dogs with two copies of this gene can also have a range of abnormalities in their spinal vertebrae, including hemivertebrae, which is why we characterise this trait as a disorder rather than just an appearance trait.
There is a lot of natural variation in the way the screw tail gene is expressed. Testing can be required to see how many copies of the gene are present in your dog.
Gene or region and technical reference
Gene: DVL2 (causative). Reference: Mansour et al (2018)
n. Test developed using artificial DNA, animal controls.
ST. Test developed using artificial DNA, animal cases.
Panels: groups of tests that are often ordered together
This test is not in any panels.