Dogs that can’t breathe, give birth or poop properly

Examine, a free weekly newsletter covering science with a sceptical, evidence-based eye, is sent every Tuesday. You’re reading an excerpt – sign up to get the whole newsletter in your inbox.

They call it “air hunger”; a primal, debilitating type of breathlessness. It’s a frightening feeling compared to the final few seconds of holding your breath for as long as you can. Except it happens even when you’re breathing.

Pugs and French bulldogs are two dog breeds most at risk of air hunger, struggling to breathe for much of their lives due to brachycephalic obstructive airway syndrome (BOAS), the result of narrowed nostrils and shortened muzzles purposely bred into flat-faced dogs.

About 90 per cent of Frenchies, bulldogs and pugs can’t breathe freely. And a new study has shown a wide range of breeds also suffer from BOAS.

Pekingese and Japanese Chin had similar rates of breathing problems to pugs, while more than half of Boston terriers, King Charles spaniels and Shih Tzus had some level of clinically significant breathing problems.

Despite the health struggles, French bulldogs remain the second-most popular dog in Australia. They also have a 16 times greater risk of difficult births due to their round heads and narrow hips (at least 80 per cent are born via caesarean), can suffer from chronic eye ulcers and risk spine issues which cause incontinence.

The vast majority of people who own flat-faced breeds totally adore their pups and obviously wouldn’t wish anything bad on their precious pooches. So why do we keep breeding and buying these dogs that often can’t breathe, give birth or poop properly? And what can we do about their welfare?

Kindchenschema: Powerful puppy-dog eyes

One of the going theories is that flat-faced dogs trigger strong emotional feelings because they resemble human babies.

Zoologist Konrad Lorenz gave the concept a name: kindchenschema. One experiment testing the theory found people more keenly wanted to care for babies with round faces, high foreheads, big eyes and small noses.

Research has shown animals with similar features can hack this effect, from rabbits to reptiles. This is puppy-dog eyes on a whole other level: a powerful gaze which hijacks our evolutionary drive to protect our young.

One analysis into the effect within flat-faced dogs concluded breeds including pugs and Frenchies “do show exaggeration of some, but not all, known fronto-facial ‘kindchenschema’ features, and this may well contribute to their apparently cute appearance and to their current popularity as companion animals”.

It’s a fascinating quirk of co-evolution that hormones hardwired to drive the care of human offspring have come to shape the skulls of canines. Researchers have said this psychological driver should be considered when understanding the appeal of these dogs.

“It does resonate for me as a veterinarian,” Dr Anne Quain, senior lecturer in the Sydney School of Veterinary Science, says of the theory. “I’ve seen people walking with a French bulldog in a baby harness strapped to their chest.”

But, because the babylike face also blunts a dog’s breath, she’s seen too many dogs of the same breed die of heatstroke.

“Part of the issue with that is that we are practicing a form of unnatural selection,” she says. “I think a lot of people just don’t appreciate that that cute appearance predisposes these particular dogs to chronic oxygen deprivation.”

Research has shown breed loyalty and emotional ties between people and flat-faced dogs is particularly strong; one study found 93 per cent of flat-faced dog owners will opt for the same breed again despite severe health risks.

The fact that unending love for these dogs drives demand to breed more of them is called the brachycephalic paradox.

“I really want to stress that I think every single dog on this planet deserves the best life that we can give them,” Quain says. “They’re all beautiful dogs and their owners aren’t deliberately putting them through [health issues].”

So if knowing the health risks doesn’t discourage people from buying flat-faced dogs, what can be done?

Should we ban flat-faced dogs?

Norway banned the breeding of some short-faced dogs including bulldogs and Cavalier King Charles Spaniels in 2022. (The ban was later largely walked back.)

The new BOAS study, however, shows breathing problems go beyond a handful of notorious breeds. “For dogs struggling to excrete carbon dioxide through compromised airways, breed labels are irrelevant,” Sydney University vet professor Paul McGreevy points out.

And bans aren’t necessarily a one-way ticket to better dog welfare. There’s concern bans could drive black market breeding. French bulldogs, for example, are a valuable item (between $3000 and $8000 as a starting point) known to be traded criminally.

Dr Arthur House, a BOAS expert at Melbourne Veterinary Specialist Centre, says reaching backyard breeders who may be ignorant or uncaring of breeding standards is key to improving health.

“Reaching the people who breed these dogs is what we need to do. So if we ban them, then we can’t reach these people.”

House says progress is under way due to a measurement technique called the respiratory functional grade (RFG) scheme, which was developed by the University of Cambridge and the UK Kennel Club. It grades dogs’ BOAS risk by taking them on a three-minute run then ranking the sound of their breathing from zero to three, with higher numbers indicating more ragged breathing.

“If you are looking at buying a puppy, you really should be asking if the parents have been tested for BOAS through the RFG program,” he says. The same scheme was used to rank dogs in the new study.

McGreevy says that because the test is subjective, it’s easy to manipulate, and cautions against its use for breeding decisions.

“When a measurement tool is both subjective and temperament-dependent, breeding selection based on it amounts to selecting for test performance rather than genuine airway health,” he says.

“Dogs with genuine respiratory distress deserve evidence-based interventions.”

Vets recommend seeking out dogs from reputable breeders who are attached to clubs or other industry bodies, because they are generally stricter about standards and have the knowledge and incentive to prioritise health over looks, unlike some hobby or backyard breeders.

Says Quain: “From a science point of view, we need to stop breeding for human aesthetic purposes and breed for welfare.”

The Examine newsletter explains and analyses science with a rigorous focus on the evidence. Sign up to get it each week.