French Bulldog AdamTs3 Gene
Gene Variant AdamTS3 [Airways Oedema Gene]
Respiratory problems are common in several dog breeds, and it is especially common for short-nosed breeds to have trouble breathing. Swelling of the airways makes this problem worse.
One of the MDBA’s strategies to deal with breathing problems for brachycephalic breeds is testing for the AdamTS3 gene variant, more commonly called the Airways Oedema gene. The Gene Variant AdamTS3 contributes to breathing difficulties by causing swelling (oedema) in the airways. It is most commonly found in British bulldogs, French bulldogs, and Norwich terriers, but it has also been found more rarely in other breeds.
The airways of dogs with two copies of this gene can be more significantly impacted than those of dogs with one copy or no copies of this gene.
Discovering the frequency of one or two copies of the adamts3 gene variant in MDBA-registered French Bulldogs.
Mandatory testing for this gene was introduced by the MDBA in 2020 for all French Bulldog breeding dogs to determine the number of dogs affected by the adamts3 gene variant in the MDBA gene pool for this breed. Based on studies at that time, there was little expectation that we would find any that did not have one or two copies of this gene. We were pleased to find that only 17% of French bulldogs in the MDBA breeding population for this gene variant had one or two copies of adamts3. Each dog with one or two copies of the variant is identified, and tracking and analysis of pedigrees is initiated to look for common relatives.
Due to the relatively small percentages of affected dogs in the MDBA French Bulldog gene pool, breeder members have been advised to use the status of their breeding dogs to direct their choices in their breeding programs. Whilst no dogs have been removed or prohibited from breeding in the gene pool, breeders have been directed not to mate anything other than a clear dog to a one-copy or two-copy dog under any circumstances. This ensures that French Bulldogs suffering from this disease bred by MDBA members can’t happen.
Litters cannot be registered unless the status of each parent is known, except for semen that was stored before the start of the program. In that case, the female must have no copies of the adamts3 gene variant, and any puppies must be entered into the registry as not for breeding and not upgraded to breeding dogs until their DNA results are known and their status for this gene is verified. This can also tell us the status of the gene variant in the semen for future breeding decisions and pedigree tracking.
This ensures we maintain the breed’s genetic diversity and prevent any French Bulldog puppy from being bred that will suffer the potential consequences of having two copies of Adamts3.
Where Are We Up To?
We have seen remarkable progress in completely eliminating the risk of any dog of the French Bulldog breed bred by an MDBA breeder member suffering from this disease. Results indicate that other health problems in the breed may have been positively impacted, which is in line with studies regarding this gene.
By initiating testing and prohibiting the mating of a dog with one or two copies of this gene variant to a dog that is not clear, no dogs have been identified with two copies of this gene variant in the MDBA registry since December 2023.
Testing for the adamts3 gene variant is still required for all French Bulldogs used for breeding in the MDBA gene pool and any new dog being entered from other registries.
Any dog being collected must be tested for this gene variant before collection.
The Way Forward
The MDBA considers this genetic action plan a resounding success in this breed, and our French Bulldog breeder members can proudly take credit for their willingness to work as a team and adhere to what is required to breed for the true betterment of the breed.
Mandatory DNA testing and prohibitions on mating dogs with one or two copies of the adamts3 gene variant with dogs other than those with zero copies will remain in place.
We will continue to monitor compliance and collect and analyse data.
Puppy buyers should now be informed that they should not purchase a French Bulldog with two copies of this variant and to ensure their breeder is testing their breeding dogs for the adamts3 gene variant.
References.
- Airways Oedema AdamTS3 https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1008102
- Dog Breeding Science (Australia). https://breeding.dog/index.php?test=aoe
- Oechtering G, Schlüter C, Lippert J. Brachycephaly in dog and cat: a “human induced” obstruction of the upper airways. Pneumologie. 2010;64:450–452. doi: 10.1055/s-0030-1255513. – DOI – PubMed
- Packer RM, Tivers MS. Strategies for the management and prevention of conformation-related respiratory disorders in brachycephalic dogs. Veterinary Med (Auckland) 2015;6:219–232. doi: 10.2147/VMRR.S60475. – DOI – PMC – PubMed