Vulnerable Dog Breeds Blog Series - Blog 7

I believe strongly in health testing.

I also believe we can fool ourselves if we think a folder full of clear test results automatically makes a dog a good breeding prospect.

Health testing is evidence. Breeding for health is a much bigger judgement.

Tests answer specific questions

A DNA test can tell us whether a dog carries a particular known variant. A hip or elbow score can tell us something about joint conformation. An eye examination, heart assessment or other breed-specific screening can identify particular abnormalities at a particular point in time.

That information matters. It helps breeders reduce avoidable risk and make better-informed mating decisions.

The Kennel Club's step-by-step guide to health screening for dog breeders is a good starting point for understanding which tests apply to your breed.

But every test has a boundary. A result tells us about the condition or trait being assessed. It does not tell us that the dog is healthy in every other respect, and it certainly does not tell us that every puppy produced from that dog will be healthy.

A clear dog is not a genetically perfect dog

One of the most important ideas in genetic testing is also one of the easiest to forget: clear means clear for the thing that was tested.

A dog that is clear for one known recessive condition may still carry other variants we do not yet know about, conditions for which no useful DNA test exists, or combinations of genes that contribute to complex disease.

This is particularly important in pedigree dogs because every dog, however carefully bred, carries genetic variation. The aim of responsible breeding is not to create a mythical genetically perfect dog. It is to understand the risks we can identify and manage them without destroying the wider gene pool in the process.

Don't throw the baby out with the bath water

One of the risks when a new health test becomes available is that breeders can react too quickly.

A dog is identified as a carrier and suddenly the conversation becomes: remove that dog from breeding.

But in a vulnerable breed, that can be exactly the wrong response.

For many straightforward autosomal-recessive conditions, a carrier is not an affected dog. When a carrier is mated to a genetically clear dog, affected puppies are not expected from that particular recessive condition. That gives breeders the opportunity to reduce the frequency of the unwanted variant gradually while still retaining valuable genetics.

Because that carrier is not carrying just one gene.

It may also carry excellent temperament, longevity, fertility, sound structure, strong maternal ability, working ability, breed type or bloodlines that are already becoming scarce.

If we remove every carrier immediately, we may solve one known problem while accidentally creating another. In a small population, wholesale exclusion can reduce diversity, increase relatedness and place even more breeding pressure on the relatively small number of dogs that test clear.

That pressure can quickly turn a handful of clear dogs into the next popular sires, as explained in The Popular Sire Effect: When One Successful Dog Shapes a Whole Breed. It also pushes relatedness up, which is why it helps to understand Coefficient of Inbreeding: What It Tells You - and What It Doesn't.

That is what I mean by not throwing the baby out with the bath water.

The sensible goal is controlled change: use the information, avoid producing affected puppies where the inheritance pattern allows us to do so, and gradually move towards clearer generations without unnecessarily discarding whole families.

Not every condition is a simple DNA problem

DNA tests are particularly useful when a disease is strongly associated with a known variant and the inheritance pattern is well understood.

But many of the health problems that matter in dogs are not that simple. Hip and elbow dysplasia, some heart disease, cruciate problems, allergies, autoimmune disease and some cancers can involve multiple genes, environmental influences or both.

That means a breeder cannot reduce health to a row of green ticks on a DNA panel. Screening is part of the picture, but phenotype, family history, veterinary findings and what actually happens to relatives over time still matter.

WSAVA's Hereditary Disease Guidelines support this wider approach to health-conscious breeding and the responsible use of genetic testing.

Health lives in families, not just certificates

When I assess a dog, I want to know more than the test result in front of me.

How long did the parents live? What did they die from? What happened to littermates? Are there repeated cancers, heart problems, fertility issues, immune-mediated disease, poor temperament or structural weakness in the family? What happened in previous litters from the same lines?

Sometimes the most valuable health information is not printed on an official certificate. It is in honest records kept across generations and in breeders being prepared to talk openly about what went right as well as what went wrong.

That is especially important for conditions that appear later in life. A young dog can have an impressive set of test results and still come from a family with poor longevity or late-onset disease.

Temperament is health too

For me, temperament comes first.

A dog can have beautiful hips and a clear DNA panel and still have a temperament I would never want to reproduce.

Behaviour and emotional stability affect the dog's quality of life, the safety and wellbeing of the family living with it, and whether that animal can function as the breed is supposed to function.

Breeding for health has to include the brain as well as the body.

Structure and function matter

A health-conscious breeding decision also asks whether the dog can move, breathe, exercise, mate, whelp and live comfortably in the body we are selecting.

Extreme conformation is a useful reminder that something can be rewarded as breed type and still carry a welfare cost. If we are breeding for health, function has to remain part of the definition of a good dog.

Environment still matters

Genes are not the whole story either.

Growth rate, nutrition, body condition, exercise, injury and the way a puppy is raised can all influence how some health problems develop or are expressed. That does not mean genetics are unimportant. It means a test result should not be treated as though it operates in isolation from the life the dog actually lives.

This is one reason I am cautious about looking at a single result and deciding that it explains everything.

Longevity takes patience

Some of the information I value most cannot be known when a dog is eighteen months old.

Longevity, late-onset disease, fertility and the health of offspring reveal themselves over time.

That is another reason older dogs, stored semen and well-recorded families can be so valuable. Sometimes age tells us things no young dog's test panel can.

A breeding decision is a balance

Health testing should absolutely influence breeding.

But I want it sitting beside temperament, structure, movement, family history, longevity, fertility, genetic diversity, environmental context and the needs of the wider population.

The goal is not to produce dogs that are simply “clear” on paper.

The goal is to produce dogs that can live healthy, functional lives - while leaving the breed enough genetic diversity to keep improving for generations to come.

Breed preservation does not stop with breeders. Puppy owners become ambassadors for the breed. Their experience - the health, temperament and support they receive, and the dog they live with every day - shapes how other people see that breed. A good experience can spark interest, create future homes and sometimes future breeders. In a vulnerable breed, every positive ambassador matters.

Founder perspective

I am Fiona Robertson, founder of Newflands. My perspective comes from decades of living with, breeding and studying dogs, my background as a veterinary nurse, and years spent researching pedigrees and bloodlines in New Zealand and overseas.

This series is not about pretending there is one perfect formula for breeding. It is about opening up the conversations that matter when the population is small and every generation can change the choices available to the next one.

Next in the series: What Does It Really Cost to Preserve a Rare Breed?

FAQs

Does health testing guarantee healthy puppies?

No. Screening can reduce known risks, but it cannot identify every genetic variant, future disease, temperament issue or environmental influence.

Should carrier dogs always be removed from breeding?

Not necessarily. For many simple autosomal-recessive conditions, a carrier can be mated to a clear dog without producing affected puppies for that condition. In a vulnerable breed, immediately excluding every carrier can unnecessarily shrink the gene pool. The aim should be to manage the known variant responsibly and reduce it over generations without throwing away valuable genetics at the same time.

Is temperament part of breeding for health?

Yes. Stable temperament and behaviour are important to welfare and to a dog's ability to function safely in everyday life.

Why does family history matter if a dog passes its tests?

Some conditions are complex, late-onset or not covered by a simple test. Longevity and patterns across parents, siblings and offspring can reveal risks that one individual result cannot.

What is health-conscious breeding?

It means using validated screening and veterinary information alongside temperament, function, conformation, family history and genetic diversity to reduce avoidable disease without unnecessarily shrinking the population.