Dvl2 and CDDY elimination in French Bulldogs - What you MUST know

Understanding that both genes work closely alongside one another, but are responsible for very different spinal implications.

In recent years, many French Bulldog breeders have begun talking about “DVL2 and CDDY gene elimination” as a way to reduce congenital hemivertebrae and significantly lower the risk of IVDD (Intervertebral Disc Disease). It sounds reassuring - and scientific. But what does it actually mean? And how much of it is proven science versus marketing language?

To understand the claim, we need to look at the two genes separately and examine what current research really tells us.

DVL2 (Dishevelled 2) is part of a gene pathway involved in skeletal development. A specific mutation in this gene has been identified in screw-tail breeds such as Bulldogs and French Bulldogs. It is associated with certain body traits that define the breed’s compact, bulldog-type structure.

French Bulldogs are well known for their screw tail and tightly compact conformation. However, screw-tail formation and vertebral malformations often appear together. Hemivertebrae - a condition where vertebrae are abnormally shaped - are very common in the breed and can lead to spinal instability or neurological problems in severe cases.

Alot of scientific, peer reviewed research has linked the DVL2 mutation to bulldog-type skeletal features, and because vertebral malformations are more common in screw-tail breeds, a small but growing number breeders have begun targeting DVL2 in their breeding programs.

Although here is the critical reality: yes, removing or selecting against DVL2 does garuntee a better and straighter spine, but it does not automatically eliminate hemivertebrae. To date (Mar 2026) there have been 1 or 2 heterozygous french bulldogs radiographed in Australia who were still found with a single minor hemivertebrae. Thats because vertebral malformations are influenced by multiple genetic factors, developmental biology, and overall conformation selection. While DVL2 does contribute to certain skeletal traits, it is not a single on/off switch for congenital spinal defects... however, i know that id much rather a <1% incidence from the dvl2 elimination genepool as opposed to the 95% incidence thatwe have sadly seen in the majority of frenchies bred today.

When a breeder claims “DVL2 elimination ensures no hemivertebrae,” that statement has been proven to be scientifically overstated. At best, careful genetic selection definitely reduces structural risk - and gives a far FAR better occurrence of a perfect vertibral column- but it cannot guarantee absolutely zero occurrence.

Dvl2 DOES have a correlation with causing ivdd. As we know, in nearly all cases, the whole reason a dog is "short cobby and compact" in the first place is because its spine bones are malformed/crowded and even can be truncated, conditions better known as either scoliosis, lordosis and kyphosis which all are caused by the dvl2 gene. It significantly impacts the intervertebral discs by altering the mechanical forces thats applied to them where the malformations are, often resulting in the exact same premature degeneration (as cddy), reduced disc height, and structural deformities. These conditions disrupt normal spinal alignment, causing uneven, chronic loading that accelerates the wear-and-tear process, which can lead to spinal instability, nerve compression, pain and Type 3 ivdd.

CDDY refers to a genetic variant associated with chondrodystrophy, the condition responsible for short limbs and a compact body style in many breeds. More specifically, it is linked to an FGF4 retrogene insertion on chromosome 12.

This genetic insertion has been strongly associated with Hansen Type I IVDD, a form of disc disease where intervertebral discs degenerate early and may rupture or herniate. IVDD is a serious condition that can cause pain, nerve compression, mobility issues, and in severe cases, paralysis.

Unlike DVL2, the science around CDDY and IVDD is much deeper and clearer. Studies have shown that dogs carrying the chromosome12 on the FGF4 insertion have a significantly increased risk of disc degeneration.

This means selective breeding to reduce or avoid CDDY-positive pairings can realistically lower IVDD risk in future generations. It does not eliminate risk entirely - because environment, weight management, activity level, and other genes also play roles - but it absolutely can substantially reduce the genetic predisposition to the early onset ivdd.

However, there is another important factor: genetic diversity.

French Bulldogs already have a limited gene pool. If a large percentage of the breed carries a particular variant, aggressively eliminating it without a structured plan can shrink genetic diversity and create new health problems.

Responsible breeding does not simply “wipe out” genes. Ethical programs test breeding dogs, avoid high-risk pairings, perform spinal X-rays, track offspring outcomes, and maintain diversity within their lines. This may take decades before there is enough genetic diversity to successfully eliminate both genes completely but the work that's been done in the last 6 years over just a few generationshas been phenomenal and absolutely groundbreaking for the health and future of the French Bulldog breed.

Can DVL2 and CDDY elimination guarantee a perfectly healthy French Bulldog? No responsible geneticist would make that claim, but all the research to date indicates and strongly suggest lsthat we are definitely on the right track to significantly reduce the incidence of spinal issues by removing BOTH of these genes.

What selective breeding can do is, reduce IVDD risk when CDDY is properly managed and reduce extreme structural traits that are linked to spinal anomalies due to the DVL2 gene. What it cannot do is guarantee zero hemivertebrae, zero IVDD, or eliminate all spinal risk with a single genetic adjustment.

Health in dogs is multifactorial. Genetics, conformation, nutrition, muscle conditioning, weight management, and environment all contribute.

The healthiest future for French Bulldogs will not come from marketing buzzwords. It will come from informed, science-based breeding practices combined with proper screening, transparency, and long-term health monitoring.

Science can reduce risk. It cannot eliminate biology. This is exactly what we are working on right here at Mightyburns Bulls. BOTH of these genes must be removed to significantly lower the risks!

That's why is 💯 important to remove BOTH cddy AND dvl2. I know alot of people dont like tails with the dvl2 gene or the pointier ears with the cddy clears but unfortunately that's part of the parcel in which Mightyburns Bulls has learned how to embrace.

Bottom line is, nowadays, continuing to breed from and produce dogs with both a terrible vertibral column due to dvl2 AS WELL AS 1 or 2 copies of the cddy gene is irresponsible when we know better and can do better. Currently in Australia, the cddy gene is like a needle in a haystack, just like dvl2 was 3-4 years ago but in time there will be more genetic diversity and its something more breeders really should get on board with.💖

You can read a little bit about our very own upcoming Dvl2 + Cddy elimination pairing over on our upcoming litters page.