Are Crossbreeds Healthier? What the Science Really Says

Few questions spark more debate among dog lovers, breeders, and veterinarians than this one: are crossbreeds healthier than purebred dogs? It’s a belief so widespread that many Australians actively seek out designer crossbreeds — Cavoodles, Labradoodles, Groodles — under the assumption that mixing two breeds automatically produces a hardier, more robust animal.

But is that assumption backed by science? The answer is more nuanced — and more interesting — than a simple yes or no.

The Origins of the “Crossbreeds Are Healthier” Belief

The idea that crossbred animals are biologically superior has a long history rooted in the concept of hybrid vigour, also known as heterosis. In scientific terms, hybrid vigour refers to the phenomenon where offspring from two genetically distinct parents display enhanced traits — better health, greater vitality, or improved reproductive success — compared to either parent breed.

The study of heterosis traces back to Charles Darwin, who was among the first scientists to examine it systematically. In livestock farming, the principle has been applied successfully for generations: crossing two distinct cattle breeds, for example, can produce offspring with improved growth rates and fertility.

The logic applied to dogs seems reasonable: purebred dogs, which are bred from closed stud books and limited gene pools, can accumulate harmful recessive genes over generations. When two different purebreds are crossed, the thinking goes, those recessive genes are “masked” by the healthier versions inherited from the other parent — particularly in a first-generation (F1) cross.

In theory, this makes sense. In practice, the picture is far more complicated.

What Does the Latest Research Actually Show?

For years, the debate over crossbreed versus purebred health lacked robust, direct scientific evidence. That changed significantly in 2024 when researchers from the Royal Veterinary College (RVC) in the United Kingdom published a landmark study in the journal PLOS ONE.

The study surveyed approximately 9,400 dog owners. Some owned designer crossbreeds — specifically Spoodles, Cavapoos, and Labradoodles — while others owned purebred “progenitor” breeds: Cavalier King Charles Spaniels, Cocker Spaniels, Labrador Retrievers, or Poodles. All dogs were under five years of age. Researchers then compared the odds of 57 common health disorders across the crossbreeds and their founding breeds — making 342 individual health comparisons in total.

The findings were striking in how unremarkable they were.

In 86.6% of health comparisons, the likelihood of any given disorder did not differ significantly between the crossbreeds and their purebred counterparts. Crossbreeds showed a higher risk in roughly 7% of comparisons and a lower risk in about 6% — a near wash. The conclusion: there was no compelling evidence of hybrid vigour in these designer crossbreeds, but equally no evidence that purebreds were significantly healthier.

As senior paper author Rowena Packer stated: “Although the health of designer poodle-crosses is no worse than their parent breeds, it is also no better.”

So Are Any Differences Worth Noting?

Yes — and they’re worth understanding if you’re a buyer or breeder.

The RVC study found some specific differences worth noting:

• Ear infections were more common across all three poodle crossbreeds compared to their non-poodle parent breeds — likely a consequence of inheriting the poodle’s ear anatomy.
• Dietary indiscretion, vomiting, and diarrhoea were more prevalent in all three crossbreeds compared to the poodle parent.
• Spoodles showed a higher likelihood of itchy skin, often linked to allergies.
• Both Labradoodles and Spoodles showed a lower risk of certain conditions compared to some of their parent breeds.

These aren’t reasons to panic, but they are reminders that crossbreeding doesn’t erase health risks — it reshuffles them.

The Genetics Explained: When Hybrid Vigour Works (and When It Doesn’t)

Understanding why hybrid vigour is so inconsistent in dogs requires a look at how genetic diseases are actually inherited.

Recessive genetic diseases will also benefit from crossbreeding. For these genetic issues, a dog must receive two copies of the faulty gene to develop that disease. By crossbreeding two different breeds, the likelihood of the puppies receiving two copies of the same recessive gene is greatly reduced.

However, this benefit comes with some drawbacks:

1. Both parent breeds may carry the same disease genes. If a Cavoodle’s Cavalier parent and Poodle parent each carry the genes for the same condition, the crossbred dog can still inherit that genetic predisposition. Breeding different dog breeds together does not eliminate the genes for specific conditions.
2. Not all diseases are single-gene recessive. Many conditions have a genetic cause, whether polygenic (multiple genes) or caused by a single dominant gene. Breeding dogs of different breeds provides no protection against these genetic conditions.
3. Hybrid vigour weakens in subsequent generations. The heterosis effect is strongest in the F1 (first-generation) cross – a true 50/50 mix of two purebreds. However, if you breed a crossbreed to another crossbreed (from the F2 generation onward), the genetic diversity effect starts to wane. Hence, breeding a Cavoodle to another Cavoodle will not provide the same theoretical health benefits as breeding a cavalier to a Poodle to produce an F1 litter.
4. Mixed breeds can still carry genetic mutations. Research has shown that harmful genetic mutations do not just simply disappear in dogs that are mixed breeds. A large study of nearly 35,000 dogs indicated that mixed breed dogs could still be homozygous for genetic diseases, meaning that they had two copies of the same mutated gene for that specific disease, and were, therefore, affected by the disease. Thus, the assumption that dogs that are mixed breeds automatically have “clear” genetics is false.

The Real Risk Factor: Body Shape, Not Breed Type

One of the most important takeaways from recent research is that extreme body conformation poses a far greater health risk than breed status.

Dr Dan O’Neill of the RVC put it plainly: owners wanting to avoid acquiring unhealthy dogs “should instead focus on avoiding extreme body shapes (e.g. flattened faces, bulging eyes, skin folds) regardless of whether the dog is purebred or a designer crossbred breed.”

It is critical for Australian buyers to understand the rising demand for dogs with flat faces such as Pugs, Bulldogs, French Bulldogs, and brachycephalic crossbreeds. The brachycephalic features of these dogs have created a crisis for their welfare as they suffer from BOAS, which stands for brachycephalic obstructive airway syndrome. This condition causes these dogs to have breathing difficulties and a reduced lifespan of the dogs due to their inability to exercise as much as other dog breeds. If a crossbreed dog has one parent with a flat face, it is at risk of developing BOAS regardless of the genes of the other parent.

What This Means for Responsible Breeders in Australia

Here in Australia, responsible breeding — whether of purebreds or crossbreeds — is guided by animal welfare legislation and a growing culture of genetic health testing.

Animal Care Australia has made it clear that non-pedigree breeders should provide the same level of care and consideration to their dogs as do pedigree breeders. The welfare and care of the dog should always come first, regardless of whether the dog is pedigree or not.

For both purebred and crossbreed dog breeders, best practice includes:

Health testing both parents. Before breeding occurs, both the male and female dogs to be bred should be genetically screened for conditions that are common to their breeds. For Cavoodles, the Cavalier should be screened for mitral valve disease and syringomyelia, while the Poodle should be screened for conditions like progressive retinal atrophy. A company like Orivet, which can screen for over 250 genetic diseases, is available to Australian breeders.

Understanding the diseases specific to each parent breed. Crossbreed puppies can have conditions from both parent breeds. Responsible breeders will research the breeds thoroughly and share that information with buyers.

Avoiding extreme conformations. Breeders should never select for flat faces, folds, or any other feature that compromises the breed’s welfare – in any breed or crossbreed.

Transparency with buyers. Breeders will provide test results, veterinary clearances, or information regarding the puppy’s dam and sire without being asked to do so. Buyers have a right to know, and breeders should be proud to provide this information.

Considering the generation of the cross. If hybrid vigour is part of the breeding rationale, an F1 cross (purebred to purebred) offers the strongest theoretical genetic diversity benefit.

The Bottom Line for Pet Buyers

If you’re considering a crossbreed puppy in Australia, here’s what the evidence suggests:

• Don’t assume a crossbreed is automatically healthier. The science shows health outcomes are largely similar between well-bred crossbreeds and purebreds of the same ancestry.
• Ask about health testing. A breeder who has tested both parents for breed-relevant genetic conditions is doing far more for your puppy’s long-term health than one who simply relies on crossbreeding to “cancel out” disease risk.
• Avoid flat-faced dogs unless you’ve done serious research and are prepared for potential ongoing veterinary costs.
• Choose the breeder, not just the breed. Responsible breeding practices, good socialisation, proper nutrition, and a healthy environment have an enormous impact on a puppy’s wellbeing — often more than its genetic background alone.
• Look at the parents. Meeting the sire and/or dam, observing their health and temperament, and reviewing their test results gives you the best possible picture of what your puppy may look like as an adult.

Final Thoughts

The question of ‘are crossbreeds healthier’ does not have a simple answer – but it does have a lesson. That crossbreeds do not automatically come with health. The health of a breed is created by the breeders: which dogs are bred, what they look like, and how they are cared for when they are puppies. It is up to each breeder to provide healthy dogs with well-cared-for origins.

At ResponsiblePetBreeders.com.au, we believe every dog deserves the best possible start — and that starts with the people who bring them into the world.