In this article
You know every sound your dog makes: the sleepy snuffle, the excited snort when the lead appears, the rumbling nap beside the sofa. Familiar sounds can become part of the household background. But noisy breathing while awake at rest or during light exercise should not be dismissed as a harmless breed characteristic1.
Brachycephalic obstructive airway syndrome, or BOAS, describes breathing problems associated with a short, flat-faced head shape. Dogs can be affected to different degrees, with consequences for exercise, heat tolerance, eating and sleep. Your vet can assess what those everyday sounds mean for your dog2, 3.
The aim is to help the dog you love breathe more comfortably. You do not need to defend the breed, measure the nose or decide whether a noise is “bad enough” before describing it to the practice.
Look beyond the soundtrack
The UK Brachycephalic Working Group advises owners to treat noisy or laboured breathing at rest or light exercise as a welfare concern. Watch what your dog can do comfortably as well as what you can hear. Trouble exercising, sleeping or enjoying ordinary activities belongs in the veterinary conversation1.
Dogs Trust describes difficulty breathing, increased breathing effort, exercise intolerance and regurgitation among possible BOAS problems. Narrow nostrils, an overlong soft palate and a narrow windpipe can contribute, although not every flat-faced dog has the same features or severity. A dog's head shape tells only part of their clinical story2.
Keep the description concrete: when the noise occurs, whether the dog is awake or asleep, what they were doing and how long recovery takes. “She stops twice on our short walk and stands panting” gives the vet more to work with than “She has always been a noisy dog.”
What the shape studies tell us
A 2015 study examined 700 dogs of varied shapes, followed by 154 flat-faced dogs from non-referral settings. Shorter relative muzzle length was associated with greater BOAS risk, with neck girth and excess body condition also contributing. This connected outward shape with breathing function, while showing that risk varied between breeds5.
Its measurements were research tools, not a home diagnostic test. A relationship seen across study populations cannot tell you that a particular dog is clear of obstruction because their nose looks a little longer than another dog's. The study supports taking conformation seriously; it does not replace examination5.
Cambridge researchers then studied 604 Pugs, French Bulldogs and Bulldogs, assessing breathing before and after controlled exercise. Narrowed nostrils were associated with BOAS in all three breeds; higher body condition was associated in Pugs and Bulldogs. Many tape-measure ratios had limited agreement between observers, restricting their usefulness for judging an individual dog6.
That 2017 paper recommends combining external features with clinical breathing assessment. It also notes limitations in validation data and recruitment. An appealing photograph of open-looking nostrils is not a certificate for the rest of the airway, and a single measurement is not a complete breathing assessment6.
The evidence now extends beyond the familiar three
A 2026 Cambridge study assessed 898 dogs from 14 further breeds, including Pekingese, Japanese Chins, Boston Terriers and Shih Tzus. The frequency and severity of breathing abnormalities varied substantially between breeds. Across the sample, higher body condition, narrowed nostrils and shorter relative muzzles were associated with BOAS status7.
Owners volunteered their dogs through appointments, shows and health-testing days, so this was not a random survey of all UK pets. The researchers also distinguish mild respiratory signs from clinically significant disease. Saying “some breathing abnormality” is not the same as saying that every affected-looking dog needs surgery7.
The findings support asking about the individual dog, including dogs outside the best-known breeds. They do not offer a reliable ranking for choosing a particular puppy's future health, or a reason to dismiss signs in a breed whose study sample happened to fare better7.
Ask what a breathing assessment involves
The Royal Kennel Club and University of Cambridge Respiratory Function Grading Scheme uses specially trained vets. They listen to breathing while the dog is settled, assess an exercise phase and listen again before assigning a grade. Assessment is available from 12 months, with repeat assessments recommended because function can change4.
The current scheme lists 17 breeds, including the original Pugs, French Bulldogs and Bulldogs, plus breeds such as Pekingese and Boston Terriers. Grades 2 and 3 indicate clinically affected dogs needing monitoring or treatment. The scheme helps guide a professional discussion; it should not become a self-administered exercise challenge at home4.
Before the appointment, write down the question you most want answered. Is the walk comfortable? Is sleep being interrupted? What should change now, and when will the team review it? A short ordinary-life account keeps the focus on your dog's experience, even if the consultation introduces unfamiliar terminology.
The scheme also cautions that breeding from assessed parents cannot guarantee an unaffected puppy. Health information helps reduce risk, but a grade is not a lifetime promise. If you are considering a dog, ask to see the actual results and discuss the wider health picture with a vet4.
Make everyday activity fit the dog
Dogs Trust recommends weight management and avoiding excessive exercise, especially in warm weather, with treatment chosen according to severity. Make a plan with your vet that allows appropriate activity while respecting breathing limits. Aim for comfortable participation in life, without using exhaustion as a fitness goal2.
A VetCompass study examined records from 905,543 UK dogs under veterinary care in 2016. Flat-faced skull shape was associated with higher odds of heat-related illness. This was an observational records study, so its results cannot give you a universally safe walking temperature or forecast a particular dog's tolerance8.
The study also found risks beyond flat-faced breeds, underlining that heat care matters for all dogs. For your own dog, discuss how weather, exertion, health and body condition change the plan. These factors are reasons to tailor an outing, not to compare what your dog “should” manage with a neighbour's8.
One useful household agreement is what to do when the dog wants to continue but someone is concerned. Let ending the outing be an ordinary option, without a debate about whether the dog has earned enough exercise. You can plan another kind of shared activity with the team’s advice in mind.
Surgery can help, with a proper discussion of limits
PDSA's current guidance explains that surgery can improve breathing and quality of life but cannot remove every effect of BOAS. It may address narrowed nostrils or excess soft-palate tissue. Anaesthesia and recovery carry particular breathing risks, and some dogs need specialist assessment or treatment3.
Ask what the proposed procedure is expected to improve, which problems may remain and what recovery will involve. A helpful explanation makes both the likely benefit and the uncertainty clear. It should also leave you knowing who to contact if the dog has difficulty after returning home.
Questions for your veterinary plan
The most useful change may begin with a sound you have heard for years. Mention it, describe the circumstances and ask what comfortable breathing should look like for your dog. Familiarity is a good reason to notice a change, and a good starting point for getting help.
Sources and further reading8 sources
The small numbers in the article link to the source behind each fact. Sources open on their own websites.
- Noisy breathing in flat-faced (brachycephalic) dogs at rest or light exercise is never normal
- Brachycephalic dogs and BOAS
- BOAS - breathing problems in flat-faced dogs
- Respiratory Function Grading Scheme
- Impact of Facial Conformation on Canine Health: Brachycephalic Obstructive Airway Syndrome
- Conformational risk factors of brachycephalic obstructive airway syndrome (BOAS) in pugs, French bulldogs, and bulldogs
- A cross-sectional study into the prevalence and conformational risk factors of BOAS across fourteen brachycephalic dog breeds
- Incidence and risk factors for heat-related illness (heatstroke) in UK dogs under primary veterinary care in 2016