ADAMTS3 for British Bulldog Breeders in Australia

Marchant et al. (2019) identified an ADAMTS3 c.2786G>A missense variant relevant to canine upper-airway disease risk and reported the risk allele in Bulldog and French Bulldog populations. That is the finding the test is built on, and it is the limit of what the test reports.

For a breeder, the practical value is not the science label. It is that copy status is inherited in a predictable pattern, so the result changes what a given pairing can produce. That makes ADAMTS3 a decision input at four specific points: buying main-register stock, selecting a stud, deciding whether a dog should be bred from at all, and repeating a previous pairing.

A result sitting in an email does not protect a breeding program. A result used inside a pairing decision can.

0-copy is the lowest documented genetic risk category for this marker. It is not a statement about the dog's structure, breathing, temperament or reproductive suitability, and it is not a breeding pass. A 0-copy British Bulldog can still be the wrong dog for the program.

1-copy means the dog carries one copy and will pass it to approximately half of its offspring. The result narrows which mates are appropriate rather than ending the conversation. Within the Hollywood Bulldogs AUS program a 1-copy dog may be used only against a 0-copy mate, and only where the whole-dog assessment supports the pairing.

2-copy means the dog inherited a copy from each parent and will pass one copy to every puppy. Hollywood Bulldogs AUS does not own 2-copy breeding dogs. For an outside breeder with a 2-copy dam, the result is not a reason to stop breeding her; it is the reason the next stud decision carries weight.

The dam's result never stands alone. The dam's result and the stud's result must be read together, because the pairing determines the outcome.

Copy status follows standard single-marker inheritance, so a breeder can state the expected distribution of a litter before the mating happens. Actual litters vary around these proportions, particularly in small litters.

Hollywood Bulldogs AUS does not use 1-copy × 1-copy pairings because that mating can produce 2-copy puppies for this tested marker. The row is included so breeders understand the arithmetic, not as a pathway the program uses.

Hollywood Bulldogs AUS uses Dog Breeding Science ADAMTS3 testing and records the result against each dog in the program. The policy applied to those results is fixed rather than negotiated litter by litter.

ADAMTS3 copy status is confirmed for both dogs before a mating is planned. 0-copy × 0-copy may be used. 0-copy × 1-copy may be used where structure, breathing, temperament, wider DNA results, pedigree, reproductive suitability and whole-dog quality support the decision. 1-copy × 1-copy is never used. Hollywood Bulldogs AUS does not own 2-copy breeding dogs.

Program history includes Australia's first identified 1-copy female, Australia's second identified 1-copy male and early 0-copy British Bulldog males, verified through the MDBA Breeding for Health Genetic Action Plan. Dr. Norman, BVSc provides independent veterinary assessment of Hollywood Bulldogs AUS breeding stock, and sire and dam documentation is issued with each litter alongside individual puppy records.

Registered breeders with 1-copy or 2-copy dams are welcome to bring the result into the stud conversation before semen is booked. Hollywood Bulldogs AUS is a Brisbane, Queensland British Bulldog breeding program and an MDBA member (#18715) offering stud access to breeders Australia-wide.

Upper-airway function in a brachycephalic dog is influenced by nostril shape, palate and airway soft tissue, tracheal dimensions, body condition, conditioning, heat exposure, age and management, alongside genetic factors that are not covered by this single marker. Packer et al. (2015) documented the conformational contribution to brachycephalic obstructive airway syndrome independently of any single gene test.

A breeder should therefore never present ADAMTS3 testing as a breathing guarantee for a puppy. The honest statement is narrower: the test reports copy status for one variant associated with upper-airway disease risk, and Hollywood Bulldogs AUS uses that result alongside functional and veterinary assessment.

Gene-only selection is as incomplete as colour-only selection. Both replace the dog with a single attribute.

The stud affects every puppy in the litter, so his ADAMTS3 result should be confirmed before semen is booked, before progesterone timing creates pressure and before colour or availability narrows the shortlist.

For a breeder with a 1-copy dam, a 0-copy stud is the only pairing Hollywood Bulldogs AUS will support, because it removes the possibility of 2-copy puppies for this marker. For a breeder with a 2-copy dam, a suitable 0-copy stud produces a litter that is entirely 1-copy for this marker, which is the single largest change available to that breeder in one generation.

Copy status is a filter, not the decision. Once the pairing is genetically sound, the stud still has to suit the dam on structure, breathing, temperament, pedigree and program direction. Breeders can model a proposed pairing with the DNA pairing calculator before enquiring.

Results kept only in an inbox or a screenshot are difficult to retrieve at the moment they are needed, which is usually when a dam is in season and a decision is being made quickly. A written record turns the result into something the program can act on months later.

Both errors come from reading the result on its own. One inflates a single marker into a whole-dog assessment; the other discards information that changes which mates are appropriate.