French Bulldog BOAS: Signs, Grades, Surgery and Daily Care

Sources: Hinze et al., Companion Animal Health and Genetics, 2025; Liu et al., PLOS ONE, 2015; Hall et al., Scientific Reports, 2020.

Most Frenchie parents love the snoring. It’s part of the charm, along with the snorts, the grunts and the dramatic sighs. But those sounds come from air squeezing through an airway that’s too small for the tissue packed inside it. For some French Bulldogs that means little more than noise. For others, French Bulldog BOAS means struggling on warm days, poor sleep, regurgitation and a real risk of heatstroke.

This guide covers the genetics, how common BOAS really is, the official grading test, heat, sleep, digestion, weight, surgery and daily care, plus breeders, insurance and where experts disagree. For the breed’s other inherited risks, see our French Bulldog health problems guide.

Affiliate disclosure: some product links in this guide are Amazon affiliate links. As an Amazon Associate, BFB earns from qualifying purchases, at no extra cost to you. It never changes what we recommend.

What Is BOAS, and Why Are French Bulldogs Prone to It?

BOAS is a breathing disorder of flat-faced dogs. Selective breeding shortened the French Bulldog’s face, but the soft tissue inside didn’t shrink to match, so narrow nostrils, a long, thick soft palate and crowded throat tissue block the airway. Two inherited gene changes, in SMOC2 and BMP3, are linked to the short face. Over time, hard breathing can cause further changes in the throat.

Brachycephalic means short-headed. In a French Bulldog, airflow can be blocked at several points: pinched nostrils (stenotic nares), a soft palate that’s too long and thick for the mouth, crowded tissue in the nose and throat and, in some dogs, a narrow windpipe. Air has to be pulled hard through those tight spots, and that effort is what makes the familiar snorts and snores.

Over time, that extra suction can cause secondary changes. Small pouches in the voice box (the laryngeal saccules) can be pulled inward, and in some dogs the cartilage of the larynx begins to collapse. Hemopet, founded by Dr. Jean Dodds, describes this same chain, from narrowed anatomy to secondary saccule eversion.

The genetics, honestly. Two inherited changes are linked to the short face of flat-faced breeds:

• SMOC2. A piece of mobile DNA inserted into the SMOC2 gene was found on about 92% of chromosomes from brachycephalic dogs, compared with about 2% from other dogs. In the 374 dogs studied, this variant explained about 36% of the variation in face length (Marchant et al., 2017). The figures are per chromosome, not per dog, and few small flat-faced breeds were included.
• BMP3. A change in the BMP3 gene is nearly fixed in the most extreme flat-faced breeds, and the paper names the French Bulldog in that group (Schoenebeck et al., 2012). The study didn’t put a number on how much of the face shape it explains, and a later study couldn’t replicate the link (Marchant et al., 2017).

A dog’s visible shape also tells you a lot. In a Cambridge study of 214 French Bulldogs, outside shape mattered: three in four had moderately to severely narrowed nostrils, which raised the odds of clinical BOAS more than fivefold, and males had about twice the odds of females. All four Frenchies with a relatively longer muzzle were graded clear (Liu et al., 2017a). So careful breeding can make a difference.

How Common Is BOAS in French Bulldogs?

Very common, though the numbers depend on who’s counting. About 59% of French Bulldogs in a Cambridge research sample were clinically affected on an exercise test. In a 2025 German owner survey, 64% described BOAS-type signs, yet only 13% had a vet diagnosis. In UK breed-scheme grading, mostly of breeding dogs, 16% were clinically affected.

Different studies measure different things. Researchers who examine every dog with an exercise test find the highest rates. In the Cambridge study of 214 Frenchies, 58.9% graded BOAS-positive, meaning Grade 2 or 3 (Liu et al., 2017a). Owner surveys land close to that on signs but far lower on diagnosis. In a survey of 574 German Frenchie owners, 64% described signs that met the study’s BOAS definition, 78% said their dog snored in its sleep and 49% reported heat intolerance, but only 13% had a formal vet diagnosis. Nearly one in four dogs had had or were booked for airway surgery (Hinze et al., 2025). The survey relied on owners’ reports, so read it as a snapshot.

Everyday vet records catch far fewer. In UK primary-care records of 2,228 young French Bulldogs (median age 1.3 years), BOAS was recorded in just 2.4%, which the authors suggested reflects only severe cases being diagnosed (O’Neill et al., 2018). A later study from the same research group found Frenchies had about 31 times the odds of a BOAS diagnosis compared with other dogs (O’Neill et al., 2021).

The BOAS Diagnosis Gap in French Bulldogs

Share of Frenchies affected, by how researchers counted. Different studies and countries, so compare with care.

• Owner-reported BOAS signs (Germany, 574 dogs)64%
• Clinically affected on an exercise test (UK research, 214 dogs)59%
• Formal vet diagnosis (same German survey)13%
• BOAS in UK primary-care records (2,228 dogs)2.4%

What about dogs graded for breeding? The UK’s Royal Kennel Club and University of Cambridge run an official Respiratory Function Grading Scheme (RFGS), which began in 2019. By the end of 2024, 1,831 French Bulldogs had been graded. Nearly half were Grade 0, and 16% were clinically affected (Grade 2 or 3). That looks far better than the research samples, but most were breeding dogs whose owners chose to test them, likely a healthier group than pet Frenchies overall. That caveat is ours; the report doesn’t make it.

UK Breathing Grades for 1,831 French Bulldogs

Royal Kennel Club RFGS results to December 31, 2024. Mostly breeding dogs whose owners chose to test, so not the typical pet Frenchie.

• Grade 0: clinically unaffected (846 dogs)46%
• Grade 1: mild, unaffected (701 dogs)38%
• Grade 2: clinically affected (253 dogs)14%
• Grade 3: severely affected (31 dogs)2%

So a clear airway isn’t rare among carefully bred, graded Frenchies, but it’s less common in pets. And comfort at rest isn’t proof: even Frenchies with no obvious signs moved less air per minute than long-nosed dogs in a Cambridge breathing study (Liu et al., 2016).

Signs of BOAS in French Bulldogs (and Why Owners Miss Them)

Common signs of BOAS include snoring, snorting or noisy breathing while awake, tiring quickly on walks, struggling in warm weather, disturbed sleep and regurgitation or vomiting. Many owners see these as normal for the breed. In one Cambridge study, 18 of 30 owners of Frenchies that tested BOAS-positive said their dog rarely or never breathed noisily or struggled on walks.

This is the heart of the problem. In the Cambridge study, researchers graded 70 owner and breeder Frenchies with an exercise test. Of the 30 that graded BOAS-positive, 18 owners said their dog never or rarely made loud breathing noises or had trouble breathing during exercise. The authors put it plainly: 60% of owners failed to recognize BOAS (Liu et al., 2015). It’s one UK sample, but a Danish survey points the same way: nearly two in three owners of French Bulldogs thought their own dog was healthier than other Frenchies (Proschowsky et al., 2025).

We miss it because we’ve been taught Frenchies are supposed to sound this way. Hemopet, founded by Dr. Dodds, is direct: snoring and snorting aren’t normal. That doesn’t mean every snoring Frenchie needs surgery. It means the sounds deserve a proper look.

What to Notice at Home, and What to Do About It

This isn’t a self-grade. Use it to decide when to book a check. Only a trained vet can grade BOAS.

• Snores in deep sleep, but breathes quietly when awake and resting and settles fast after play→Mention it at the next checkup; book an official grade from 12 months
• Snorts or breathes noisily while awake, even when calm→Book a BOAS assessment
• Lags or stops on walks, is slow to settle afterward or struggles on warm days→Book a BOAS assessment; shorten walks and avoid heat
• Brings food back up, vomits, gags or drools a lot, especially after meals or exercise→See your vet and ask about BOAS and the gut
• Wakes gasping or seems to stop breathing for moments in sleep→See your vet soon; a video of the sleep helps
• Struggles to breathe, has blue or gray gums, collapses or can’t cool down→Emergency: call your vet or emergency clinic now

How BOAS Is Graded: The 3-Minute Trot Test

BOAS is graded 0 to 3 with the Respiratory Function Grading Scheme (RFGS), run by the OFA in the U.S. and the Royal Kennel Club in the UK. A trained vet listens to your dog’s throat, has your dog trot briskly for 3 minutes, then listens again. Grades 0 and 1 are clinically unaffected; Grades 2 and 3 are clinically affected. Dogs must be at least 12 months old.

The scheme grew out of University of Cambridge research that checked vets’ grades against whole-body barometric plethysmography, an objective breathing measurement taken in a sealed chamber (Liu et al., 2015; Liu et al., 2016). In the U.S., the Orthopedic Foundation for Animals (OFA) licenses the same scheme. Here’s how the OFA exam works:

• A breathing history. You fill in a short survey about your dog’s breathing history.
• A calm exam. The vet listens over your dog’s throat with a stethoscope.
• A 3-minute trot. Your dog trots at about 4–5 mph. The OFA notes that dogs should not be pulled, and the test stops if your dog shows distress. A dog already in distress or with blue-tinged gums is graded 3 without the trot.
• A second listen. The vet checks again right after exercise.

The final grade is the highest score across three areas: breathing noise, breathing effort and signs of distress such as blue gums or fainting. The minimum age is 12 months. Exams before that are preliminary only. Because BOAS can develop later, the OFA recommends yearly vet checks for dogs under 2. Grade 0 and 1 results get an OFA number and are public; Grade 2 and 3 results are public only if the owner agrees. The OFA fee is $15 plus the vet’s exam (OFA, checked October 2026).

The Four BOAS Grades

What a trained assessor looks for, and what usually comes next. Your vet makes the final call.

Grade	What the vet finds	Status	What usually comes next
0	No BOAS-related noise, even with a stethoscope	Unaffected	Routine care; suitable for breeding under the grade rules.
1	Mild noise heard only with a stethoscope	Unaffected, mild	Recheck over time; grades can change.
2	Noise you can hear without a stethoscope	Affected, moderate	Medical attention: weight control and a surgery discussion.
3	Severe noise and effort, or distress such as blue gums or collapse	Affected, severe	Cambridge researchers advised owners that these dogs need surgery. Should not be bred.

Why the trot matters. Listening to a resting dog misses a lot of BOAS. In a Cambridge validation study of pugs, French Bulldogs and English Bulldogs, a vet exam caught about 57% of affected dogs at rest, 70% after a walk and 93% after a trot. Noisy breathing heard over the voice box after exercise also flagged dogs with laryngeal collapse. The authors recommend the 3-minute trot (Riggs et al., 2019).

Can I grade my own dog? No. The value of the RFGS is a trained assessor with a stethoscope and a standard routine. What you can do is film your dog’s breathing at rest, after play and asleep, and bring it to the appointment.

Does BOAS Get Worse With Age?

It can, especially in young dogs and with weight gain, but many adult Frenchies stay at the same grade for years. A Finnish follow-up found grades mostly changed in dogs first checked before age 2, and weight gain made Frenchies’ walking tests worse. The OFA also recommends yearly vet checks until age 2.

In the Finnish study, 25 French Bulldogs, 31 pugs and 8 bulldogs were re-examined two to three years after their first assessment. Most dogs’ severity stayed the same. Where grades got worse, it was mostly in dogs first checked before 2 years of age; results were fairly stable in dogs first graded after 2. In the Frenchies, walking tests didn’t change much overall, but dogs that gained weight took longer to complete a 1,000-meter walk (Aromaa et al., 2021). In UK vet records, BOAS was recorded slightly more often in Frenchies aged 2 or older (2.9% vs 2.2%), though the difference wasn’t statistically significant (O’Neill et al., 2018).

The mechanism is well described: years of hard breathing can pull the laryngeal saccules inward and weaken the larynx. A 2026 review says most patients worsen over time, though that’s a narrative statement, not new data (Schlicksup & Phillips, 2026). We found no study putting a number on how often a Grade 2 Frenchie becomes Grade 3.

When to Check Your Frenchie’s Breathing

A simple schedule built from the grading schemes. Your vet may suggest more often.

8 wk6 mo1 yr2 yr4 yr6 yr+

Watch and noteGrade, then yearlyRecheck over time

Puppy: notice signs; keep lean12 months: official grade, then yearly to 2Adult: recheck when signs change

12 mominimum age for an official RFGS grade; earlier exams are preliminary (OFA)

Under 2yearly vet checks, because BOAS can develop later (OFA)

2 yrssuggested recheck interval for Grade 1 dogs (Schlicksup & Phillips, 2026)

Beforebreeding: grade both parents a few weeks ahead (Hemopet, 2023)

Heat is the most urgent everyday risk for a Frenchie with BOAS. In UK vet records, French Bulldogs had about 6.5 times the odds of heatstroke compared with Labradors, and about three in four heatstroke cases were triggered by exercise, not hot cars. Keep your Frenchie in cool, air-conditioned, low-humidity rooms in warm weather and walk early or late in the day.

Dogs cool themselves mainly by panting, which a blocked airway makes harder. In a study of more than 900,000 UK dogs, French Bulldogs had 6.49 times the odds of heat-related illness compared with Labradors, flat-faced breeds overall had about twice the odds of medium-muzzled breeds and about one in seven affected dogs died (Hall et al., 2020a). Among dogs with heatstroke, flat-faced dogs had about three times the odds of dying after adjusting for other risk factors (Hall et al., 2022).

Here’s the part that surprises people. In a second UK study, exercise triggered 74% of heatstroke cases. Hot weather alone accounted for 13% and vehicles for about 5% (Hall et al., 2020b). Hot cars are deadly and you should never leave a Frenchie in one. But the everyday danger is a walk, a game of fetch or a romp in the yard on a warm, humid day.

Heatstroke Odds by Breed, Compared with Labradors

UK dogs under veterinary care in 2016. Higher bars mean higher odds.

• Bulldog14.0×
• French Bulldog6.5×
• Pug3.2×
• Labrador Retriever (comparison)1×

Surgery can help with heat, too. In a small pilot study of 13 French Bulldogs, body temperature rose less during treadmill exercise after airway surgery (a median rise of 0.3°C, about 0.5°F, compared with 0.6°C, about 1.1°F, before), and heart rate was lower (Žgank et al., 2023).

Our heat rules. We don’t know of any study that sets a safe room temperature for French Bulldogs, so we won’t give you a magic number. In warm weather, keep your Frenchie in cool, air-conditioned, low-humidity rooms, walk early or late in the day, carry water and stop at the first sign of heavy panting. Skip fetch and running games when it’s warm or humid. Watch for heavy panting that doesn’t settle with rest and cool air, wobbliness, vomiting or collapse.

If you suspect heatstroke, cool first and call your vet while you cool. Wet your Frenchie all over with cool tap water, or sit them in cool water with the head supported, add a fan and skip the ice. UK vet researchers call the fear of cool water a myth and advise cooling first, then transport (Hall et al., 2023). Then go in, with the car’s AC on, even if your Frenchie seems to bounce back. Our heat safety guide has the full first-aid steps, including when to stop cooling. Flat-faced dogs have higher odds of dying from heatstroke, and only a vet can check what’s going on inside. That’s our position, and it’s a firm one.

Snoring and Sleep: Sleep-Disordered Breathing

Flat-faced dogs have more blocked breathing in their sleep. In a 2024 Finnish study, brachycephalic dogs had about 5.6 times as many obstructive breathing events at night, overweight dogs about 3.5 times as many and dogs that tested BOAS-positive about 2.5 times as many. Loud snoring, gasping or restless sleep is worth raising with your vet.

The Finnish team recorded the sleep of 28 flat-faced and 35 other dogs. Being brachycephalic, carrying extra weight (body condition above 5 out of 9) and testing BOAS-positive all raised blocked-breathing events; age didn’t (Niinikoski et al., 2024). The abstract didn’t break results down by breed.

Older research in English Bulldogs found that most spent long periods with blood oxygen below 90% during sleep, worst in dream (REM) sleep, while the comparison dogs never dropped that low. The bulldogs also fell asleep during the day in about 12 minutes, compared with more than 150 minutes for the other dogs (Hendricks et al., 1987). We didn’t find comparable oxygen data in French Bulldogs. In people, repeated oxygen drops in sleep are linked to heart and metabolic problems, but that hasn’t been studied in dogs with BOAS.

Still, a Frenchie fighting to breathe all night deserves attention. To keep an eye on it, you can count your Frenchie’s breaths while they sleep using our resting breath-rate check, and our guide to sleep apnea in French Bulldogs explains the warning signs to raise with your vet.

Sleep tips. Keep the bedroom cool. Some owners find a slightly raised head position helps their dog settle. There’s no research on sleep position in BOAS, so treat that as comfort, not treatment. Most important: film a few minutes of your dog asleep and show your vet. Long pauses in breathing or waking with a gasp are signs to share.

Regurgitation, Vomiting and Tummy Trouble

BOAS and digestive problems often go together in French Bulldogs. In a UK study of dogs having airway surgery, 93% of the Frenchies had signs like vomiting, regurgitation or drooling, and those signs often improved after surgery. Smaller meals, a slow-feed bowl and keeping your dog upright for a few minutes after eating can help.

Why the two go together isn’t fully settled, but the link is strong in Frenchies. In the UK surgical study of 98 dogs, digestive signs were reported in 93% of French Bulldogs, compared with 58% of English Bulldogs and 16% of pugs, and they improved after airway surgery, most notably in the Frenchies (Kaye et al., 2018). In an earlier study of 73 brachycephalic dogs, two-thirds of them Frenchies, 97% had abnormalities in the esophagus, stomach or upper small intestine on endoscopy, even some dogs without digestive signs (Poncet et al., 2005).

A 2025 study of 176 French Bulldogs with BOAS found regurgitation in 46.6%, a hiatal hernia (part of the stomach slipping up through the diaphragm) in 26.7% and at least one digestive finding in every dog. More severe BOAS went with worse digestive signs (Bottero et al., 2025). A 2026 review notes that some research suggests these gut changes may be a primary part of the breed’s anatomy, not just a side effect of breathing (Schlicksup & Phillips, 2026).

Mealtime habits that help. The BOAS owner sheet from Langford Vets, a University of Bristol-linked referral hospital, suggests smaller meals, little and often, a slow-feed bowl or lick mat, feeding from a step so the front legs are higher than the back legs and standing your dog up on the back legs for 2–5 minutes after eating. Weigh portions and change foods gradually over about a week. Don’t ignore thinness, either. About 15% of the most severely affected Frenchies in the Cambridge study were underweight, which the researchers linked to regurgitation (Liu et al., 2017a).

We believe biologically appropriate raw food (BARF) is best, though not required: fresh food is a good option, and fresh toppers are an easy first step. Kibble isn’t ideal for the canine species. No study has tested diet type in BOAS dogs, so change food slowly, with your vet, if your Frenchie regurgitates. Our French Bulldog gut health guide covers the details, our raw feeding guide goes deeper on raw and our probiotics guide explains where gut supplements do and don’t have evidence.

Why raw, and how to handle it safely. Dogs have a strongly acidic stomach, a short and simple gut and scissor-like back teeth made for meat, and they have no set need for dietary carbs (Kook et al., 2014; Deschamps et al., 2022; Kayser et al., 2024). That’s why complete and balanced raw is our first choice for healthy dogs in suitable homes. It isn’t risk-free: raw meat can carry germs like Salmonella, and healthy raw-fed dogs can carry them in their stool without looking sick (Groat et al., 2022).

Handle it like raw meat for your family: thaw it in the fridge and wash bowls, counters and hands after every meal. If your home includes children under 5, adults 65 or older, anyone pregnant or anyone with a weakened immune system, or your Frenchie is a puppy, has a weak immune system or takes immune-suppressing medicine, talk with your vet first and consider HPP-treated or gently cooked food (Centers for Disease Control and Prevention).

Weight and BOAS: The Honest Picture

Keeping your Frenchie lean is one of the best things you can do for breathing. Across pugs, Frenchies and bulldogs, obesity was linked to BOAS. In Frenchies alone, nostril and neck shape mattered more than body condition, but extra weight was still linked to worse sleep breathing and walking tests, and heavier dogs had higher heatstroke odds. Lean dogs live longer.

The evidence, honestly. In a Cambridge breathing study of 100 pugs, 100 French Bulldogs and 66 bulldogs, obesity and narrowed nostrils were both significantly linked to BOAS across the three breeds (Liu et al., 2016). A UK study of two groups of dogs found thicker necks and, in one of the two groups, higher body condition raised the risk, though the authors couldn’t tell whether fat causes BOAS or worsens it (Packer et al., 2015). But when the Cambridge team looked at 214 Frenchies on their own, body condition score wasn’t a significant predictor; nostril narrowing and neck girth were (Liu et al., 2017a).

That doesn’t mean weight doesn’t matter for Frenchies. It means a lean Frenchie can still have BOAS, and extra weight was still linked to worse breathing in the studies below. Overweight dogs had about three and a half times as many blocked-breathing events in sleep (Niinikoski et al., 2024). Frenchies who gained weight walked slower in follow-up tests (Aromaa et al., 2021). And dogs at or above their breed’s average weight had about 40% higher odds of heatstroke (Hall et al., 2020a). Hemopet’s writing on obesity, by Dr. Dodds, makes the same point: extra weight raises the risk of airway obstruction in flat-faced breeds, along with heat and exercise intolerance.

How lean is lean? You should feel the ribs easily under a thin layer of fat and see a waist from above. Our French Bulldog weight guide walks you through body condition scoring, calories and a safe weight-loss plan, and our best food for French Bulldogs guide covers what to feed.

BOAS Surgery: What’s Done, How Well It Works and the Risks

BOAS surgery usually widens the nostrils, shortens and thins the soft palate and may remove everted saccules or tonsils. Most owners report an improvement: 88.5% in one study, and gains held up about four and a half years later in another. But breathing often stays below normal, there are real anesthetic risks and timing is a decision to make with an experienced surgeon.

Surgery is usually discussed for clinically affected dogs, Grade 2 and above. In the Cambridge studies, Grade 2 dogs were described as needing medical attention, such as weight control and/or surgery, and owners of Grade 3 dogs were advised that their dog needed surgery (Liu et al., 2015; Liu et al., 2017a). It isn’t cosmetic.

What’s usually done. Depending on your dog, a surgeon may combine several steps in one anesthetic:

• Nostril widening. A wedge rhinoplasty or similar procedure opens narrowed nostrils.
• Soft palate surgery. The long soft palate is shortened (staphylectomy), or shortened and thinned with a technique called folded flap palatoplasty.
• Saccule and tonsil removal. Everted laryngeal saccules or enlarged tonsils that block the airway may be removed.
• Laser-assisted turbinectomy (LATE). For some dogs who still breathe poorly after standard surgery, a laser can clear overgrown tissue inside the nose. In 20 pugs and Frenchies, it lowered the median BOAS index from 67% to 42%, and 12 of the 20 had temporary reverse sneezing (Liu et al., 2019).

How well it works. In one study of pugs and French Bulldogs after nostril and folded flap palate surgery, 88.5% of 52 owners reported improvement (Haimel & Dupré, 2015). In a long-term study of 32 dogs followed for a median of about four and a half years, improvement held. Only 1 of 16 dogs measured had a worse breathing score than before surgery. Owners said quality of life improved in 94%, breathing problems resolved in 55% and 97% would recommend surgery. That study excluded dogs who needed a second operation, so it likely looks a bit better than reality (Johnson et al., 2026).

Objective measurements are more sobering. In a Cambridge study of 50 pugs, Frenchies and bulldogs measured in a breathing chamber, the median BOAS index fell from 76% to 63% after surgery, still in the clinically affected range. Younger age and laryngeal collapse were linked to poorer results, as was the traditional surgical technique; the authors recommended a modified approach (Liu et al., 2017b). In the German owner survey, about one in four Frenchies that had airway surgery went on to have a second surgery (Hinze et al., 2025).

BOAS Surgery: The Benefits and the Limits

From studies of pugs, French Bulldogs and bulldogs. Most are small and single-center.

What surgery can do

• 88.5% of owners reported improvement after nostril and palate surgery
• 94% of owners said quality of life improved about 4.5 years later
• Frenchies’ body temperature rose less during exercise after surgery
• Digestive signs improved, most notably in Frenchies

Limits and risks

• The median breathing score stayed in the affected range after standard surgery
• 39% of owners still saw some breathing problems years later
• About 1 in 4 dogs in one hospital series had breathing complications after surgery (secondary summary)
• About 1 in 4 Frenchies in a German survey who had airway surgery went on to a second surgery

Risks and recovery. In a series of 248 brachycephalic dogs at one hospital, 23.4% had breathing complications after airway surgery and 2.4% (6 dogs) died. Each extra year of age raised the odds of complications by about 15% (Lindsay et al., 2020; figures from a secondary summary). In the long-term study, regurgitation was the main early complication, and dogs who had laser or coblation work inside the nose had reverse sneezing for three to four weeks (Johnson et al., 2026). Ask your surgeon about their own complication rates and how they manage recovery.

When to operate. Earlier isn’t proven to be better. In a small AKC Canine Health Foundation study, nostril surgery in 63 brachycephalic puppies under 6 months seemed to ease signs but didn’t reduce how many developed BOAS; no Frenchies were included. And in the Cambridge outcomes study, younger dogs did worse after surgery (Liu et al., 2017b). Get an early, formal assessment, and decide timing with a specialist.

Anesthesia, for any procedure. Flat-faced dogs face higher risks under anesthesia, not just for airway surgery. In a study of 223 brachycephalic dogs and 223 other dogs having a range of procedures, the brachycephalic dogs had 1.57 times the odds of complications during anesthesia and 4.33 times the odds after recovery (Gruenheid et al., 2018). Hemopet, founded by Dr. Dodds, cites the same risk. Always tell any vet your Frenchie is brachycephalic before an anesthetic, even for a dental or a spay. Ask how they’ll monitor breathing during recovery. Our anesthesia safety guide for French Bulldogs lists the questions to ask before any procedure.

Choosing a surgeon. Look for a board-certified veterinary surgeon or a vet with a large BOAS caseload. Ask how many BOAS surgeries they do a year, which techniques they use and what their complication and repeat-surgery rates are. As a guide to cost, Langford Vets in the UK listed a fixed-price BOAS surgery package at £3,775, including the consult, intensive care, anesthesia, surgery and medication, plus £326 for the assessment (prices correct at April 1, 2025). One U.S. insurer, MetLife, lists an average treatment cost for BOAS of $3,000–$5,000 on its French Bulldog page (checked October 2026); that’s an insurer estimate, not a surgery quote. Get a written estimate.

What it costs: our BOAS surgery cost guide lists prices for each procedure, from nostrils to soft palate, with insurer claims data and the questions to ask your surgeon.

Every Frenchie benefits from BOAS-smart daily care, whatever their grade and whether or not they’ve had surgery. Get a formal grade, keep your dog lean, keep them cool, walk in a harness at the cool ends of the day, feed smaller meals if they regurgitate and plan ahead for anesthesia and insurance.

Harness, not collar. Neck pressure is worth avoiding in a flat-faced dog. In a 2025 study, collar pressure raised eye pressure and resting breathing rate in the 10 brachycephalic dogs tested, even when standing still, while a Y-shaped harness didn’t (Bailey et al., 2025). An older study of 26 dogs found collar pressure raised eye pressure while a harness didn’t (Pauli et al., 2006). These are small studies that didn’t measure BOAS directly, but they support a harness. Our French Bulldog training guide shows how to teach relaxed harness walking with rewards, which also builds your bond.

Integrative Support: What Helps and What’s Unproven

Integrative care for a BOAS dog starts with what lightens the load on the airway: a lean body on a species-appropriate diet, a cool and clean-air home, low stress, good sleep, mealtime support for dogs who regurgitate and an integrative vet working alongside your surgeon. We haven’t seen any studies of acupuncture, massage, chiropractic or supplements for BOAS itself, so they’re add-ons, never a substitute for grading or surgery.

We’re an integrative site, which is exactly why we want to be honest here. A root-cause approach to BOAS starts with the everyday things that change how hard your Frenchie has to work to breathe. Here’s where we’d put your energy first:

• A lean body on real food. Extra weight was linked to worse sleep breathing and walking tests in the studies above, and lean dogs live longer. A complete, species-appropriate diet, weighed portions and counted treats make lean easier to keep.
• A cool, clean-air home. In her writing on collapsing windpipes, a problem that often travels with BOAS, Dr. Judy Morgan suggests a harness instead of anything that presses on the throat, a healthy weight, a humidifier and HEPA air filter, no smoke or scented candles and no exercise in heat and humidity. These are sensible comfort steps rather than tested BOAS treatments.
• Low stress and good sleep. Dr. Karen Becker lists lower stress alongside weight control and avoiding heat for flat-faced dogs. Calm routines, reward-based training and a cool bedroom all help a Frenchie rest.
• Gut support for regurgitators. The mealtime habits above come first. If your Frenchie keeps regurgitating, ask your conventional and integrative vets to look at the gut and the airway together.
• Ask before the nose-drop kennel cough vaccine. Dr. Morgan considers flat-faced dogs poor candidates for the Bordetella (kennel cough) vaccine given as nose or mouth drops. That’s her clinical view, so ask your vet whether your dog needs it and which form suits a flat-faced dog.

What’s unproven. These come up often, but we found no BOAS research behind them:

• Acupuncture. Some integrative vets use it for comfort. It hasn’t been studied in BOAS. The only dog airway study we found was small and uncontrolled, in dogs with a collapsing windpipe, not BOAS, and the dogs stayed on their medication throughout (Chueainta et al., 2022). If you try it, choose a certified veterinary acupuncturist.
• Chiropractic, massage and “myofunctional” therapy. You may see claims that BOAS causes spinal misalignments that chiropractic fixes, or that throat massage reduces airway restriction. We found no evidence for either, so we don’t recommend them for BOAS.
• Supplements. We haven’t seen any BOAS research on popular airway or antioxidant supplements such as quercetin, CoQ10 or NAC, so we don’t recommend any supplement as a BOAS treatment. If you use supplements for other reasons, check them with your vet first.

An integrative vet can be a great partner for diet, weight and gut health, working alongside your surgeon. You can find integrative vets in our integrative vet directory, and our allergies guide covers the skin and ear problems that are also common in this breed.

Choosing a Breeder and Getting Insured Early

The best BOAS prevention happens before you bring a puppy home. Choose a breeder who has both parents officially graded under the RFGS and breeds only Grade 0 and 1 dogs, or Grade 2 only with Grade 0 or 1. Ask for the grades and OFA numbers. Then insure your puppy early, before any breathing signs are recorded.

What to ask a breeder. Hemopet’s guidance on the OFA scheme, by Dr. Dodds, sets out simple breeding rules by grade: Grade 0 or 1 dogs can be bred to each other, a Grade 2 dog only to a Grade 0 or 1, never two Grade 2 dogs together and never a Grade 3. Parents should be graded a few weeks before breeding and reassessed about every two years while they’re being bred.

The Cambridge team also advised against breeding dogs with moderately or severely narrowed nostrils and suggested waiting on breeding decisions for young males (Liu et al., 2017a). Grade 0 and 1 results are public on the OFA website, so a good breeder can share an OFA number you can look up.

In a Danish survey, 79% of owners who’d get another French Bulldog said they’d likely prefer a puppy from BOAS-graded parents (Proschowsky et al., 2025). Look for open nostrils, and walk away from any breeder who says the snorting is “just how Frenchies are.” Dr. Karen Becker’s writing on flat-faced pets makes the same case: buy from a health-focused preservation breeder and understand the RFGS grades before you choose. Our French Bulldog breeder directory is a place to start; always ask for health testing yourself.

Insure early. Pet insurance generally won’t cover conditions that showed signs before your policy started or during its waiting period. BOAS is common in Frenchies, and nearly one in four dogs in the German survey had had or were booked for airway surgery (Hinze et al., 2025). So insure when your puppy comes home, before a vet writes “noisy breathing” or “stenotic nares” in the record, and check that hereditary conditions, including BOAS surgery, are covered. Our French Bulldog insurance guide compares plans that cover BOAS and IVDD. The spine is the breed’s other big risk; see our French Bulldog IVDD guide.

Compare insurers on BOAS: our French Bulldog pet insurance comparison tool shows which insurers name BOAS as covered, which need a rider, and which exclude it as congenital.

Where the Experts Disagree

Vets broadly agree that BOAS is common, under-recognized and worth grading. They differ on when to operate, how much weight matters in Frenchies specifically, how much surgery can really fix, whether grading is enough or breeding should be restricted and whether integrative add-ons like chiropractic have any role.

• When to operateA 2014 surgery article recommends widening narrow nostrils in puppies at 3–4 months, saying early correction may help head off later changes (Today’s Veterinary Practice, 2014), and where grades worsened in one follow-up, it was mostly in dogs first checked before age 2 (Aromaa et al., 2021). But younger dogs did worse after surgery in a Cambridge study (Liu et al., 2017b), and puppy nostril surgery alone didn’t prevent BOAS in a small AKC Canine Health Foundation study. Our take: assess early, then decide timing with a specialist.
• How much weight matters in FrenchiesAcross three breeds, obesity was linked to BOAS (Liu et al., 2016), and extra weight was linked to worse sleep breathing (Niinikoski et al., 2024). Yet in 214 Frenchies alone, body condition wasn’t a significant predictor (Liu et al., 2017a). Our take: lean is non-negotiable, but a lean Frenchie still needs a breathing check.
• Does surgery fix BOAS?Owner-reported improvement is high (Haimel & Dupré, 2015), and gains lasted years (Johnson et al., 2026). But objective scores often stayed in the affected range (Liu et al., 2017b), and some dogs need further procedures (Liu et al., 2019). Our take: surgery helps most affected dogs a lot, but expect better, not normal.
• Grade and breed, or restrict breeding?The UK and U.S. schemes rely on breeding by grade, as Hemopet’s guidance sets out. The Netherlands goes further: since 2023, adult dogs that have had airway surgery may not be bred there (Government of the Netherlands, 2023). Our take: grading is the minimum every breeder should meet.
• Integrative add-onsSome integrative vets, such as Dr. Peter Dobias, recommend a harness over any collar and value chiropractic, acupuncture and massage; as of October 2026, his site sells a harness and supplements. He also criticizes breed standards that favor looks over function, including flat faces. We found no BOAS trials of acupuncture, massage or chiropractic, and the harness data come from small studies of eye pressure and breathing rate (Bailey et al., 2025). Our take: use a harness; treat the rest as comfort measures at most.

Frequently Asked Questions About French Bulldog BOAS

Sources

Research

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3. Liu NC, Sargan DR, Adams VJ, Ladlow JF. Characterisation of brachycephalic obstructive airway syndrome in French bulldogs using whole-body barometric plethysmography. PLOS ONE. 2015;10(6):e0130741. doi:10.1371/journal.pone.0130741
4. Liu NC, Adams VJ, Kalmar L, et al. Whole-body barometric plethysmography characterizes upper airway obstruction in 3 brachycephalic breeds of dogs. Journal of Veterinary Internal Medicine. 2016;30(3):853–865. doi:10.1111/jvim.13933
5. Liu NC, Troconis EL, Kalmar L, et al. Conformational risk factors of brachycephalic obstructive airway syndrome (BOAS) in pugs, French bulldogs, and bulldogs. PLOS ONE. 2017;12(8):e0181928. (Cited as Liu et al., 2017a.) doi:10.1371/journal.pone.0181928
6. Liu NC, Oechtering GU, Adams VJ, et al. Outcomes and prognostic factors of surgical treatments for brachycephalic obstructive airway syndrome in 3 breeds. Veterinary Surgery. 2017;46(2):271–280. (Cited as Liu et al., 2017b.) doi:10.1111/vsu.12608
7. Liu NC, Genain MA, Kalmar L, et al. Objective effectiveness of and indications for laser-assisted turbinectomy in brachycephalic obstructive airway syndrome. Veterinary Surgery. 2019;48(1):79–87. doi:10.1111/vsu.13107
8. Riggs J, Liu NC, Sutton DR, et al. Validation of exercise testing and laryngeal auscultation for grading brachycephalic obstructive airway syndrome in pugs, French bulldogs, and English bulldogs by using whole-body barometric plethysmography. Veterinary Surgery. 2019;48(4):488–496. doi:10.1111/vsu.13159
9. Aromaa M, Rajamäki MM, Lilja-Maula L. A follow-up study of exercise test results and severity of brachycephalic obstructive airway syndrome signs in brachycephalic dogs. Animal Welfare. 2021;30(4):441–448. doi:10.7120/09627286.30.4.007
10. Hinze MAG, Meyer KOH, Heilmann RM, et al. Health status and disease prevalences in French bulldogs in Germany: insights from a survey-based study. Companion Animal Health and Genetics. 2025;12:9. doi:10.1186/s40575-025-00149-8
11. O’Neill DG, Baral L, Church DB, et al. Demography and disorders of the French Bulldog population under primary veterinary care in the UK in 2013. Canine Genetics and Epidemiology. 2018;5:3. doi:10.1186/s40575-018-0057-9
12. O’Neill DG, Packer RMA, Francis P, et al. French Bulldogs differ to other dogs in the UK in propensity for many common disorders: a VetCompass study. Canine Medicine and Genetics. 2021;8(1):13. doi:10.1186/s40575-021-00112-3
13. Proschowsky HF, Springer S, Lotze S, et al. Perception of dog health and attitudes towards BOAS grading among Danish owners of French bulldog. Frontiers in Veterinary Science. 2025;12. doi:10.3389/fvets.2025.1605505
14. Packer RMA, Hendricks A, Tivers MS, Burn CC. Impact of facial conformation on canine health: brachycephalic obstructive airway syndrome. PLOS ONE. 2015;10(10):e0137496. doi:10.1371/journal.pone.0137496
15. Niinikoski I, Himanen SL, Tenhunen M, et al. Evaluation of risk factors for sleep-disordered breathing in dogs. Journal of Veterinary Internal Medicine. 2024;38(2):1135–1145. doi:10.1111/jvim.17019
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17. Kaye BM, Rutherford L, Perridge DJ, et al. Relationship between brachycephalic airway syndrome and gastrointestinal signs in three breeds of dog. Journal of Small Animal Practice. 2018;59(11):670–673. doi:10.1111/jsap.12914
18. Poncet CM, Dupre GP, Freiche VG, et al. Prevalence of gastrointestinal tract lesions in 73 brachycephalic dogs with upper respiratory syndrome. Journal of Small Animal Practice. 2005;46(6):273–279. doi:10.1111/j.1748-5827.2005.tb00320.x
19. Bottero E, Ruggiero P, Falcioni D, et al. Clinical evaluation and systematic classification of endoscopic gastrointestinal findings in 176 French bulldogs with brachycephalic airway obstructive syndrome. Animals. 2025;15(14):2137. doi:10.3390/ani15142137
20. Haimel G, Dupré G. Brachycephalic airway syndrome: a comparative study between pugs and French bulldogs. Journal of Small Animal Practice. 2015;56(12):714–719. doi:10.1111/jsap.12408
21. Johnson DA, Liu NC, Ladlow JF. Comparison of short- and long-term objective respiratory outcomes after surgery for brachycephalic obstructive airway syndrome. Veterinary Surgery. 2026;55(1):59–68. doi:10.1111/vsu.70034
22. Žgank Ž, Nemec Svete A, Lenasi H, et al. The effect of the surgical treatment of BOAS on the thermoregulatory response to exercise in French bulldogs: a pilot study. Frontiers in Veterinary Science. 2023;10:1229687. doi:10.3389/fvets.2023.1229687
23. Lindsay B, Cook D, Wetzel JM, et al. Brachycephalic airway syndrome: management of post-operative respiratory complications in 248 dogs. Australian Veterinary Journal. 2020;98(5):173–180. doi:10.1111/avj.12926 (Figures as reported in a veterinary clinic summary; full paper not reviewed.)
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25. Hall EJ, Carter AJ, O’Neill DG. Incidence and risk factors for heat-related illness (heatstroke) in UK dogs under primary veterinary care in 2016. Scientific Reports. 2020;10:9128. (Cited as Hall et al., 2020a.) doi:10.1038/s41598-020-66015-8
26. Hall EJ, Carter AJ, O’Neill DG. Dogs don’t die just in hot cars: exertional heat-related illness (heatstroke) is a greater threat to UK dogs. Animals. 2020;10(8):1324. (Cited as Hall et al., 2020b.) doi:10.3390/ani10081324
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29. Bailey ME, Packer MJ, Wills AP. Effect of a collar and harness on intraocular pressure and respiration rate of brachycephalic and dolichocephalic dogs. Veterinary Medicine and Science. 2025;11(3):e70384. doi:10.1002/vms3.70384
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37. Today’s Veterinary Practice (no author listed). Corrective surgery: dogs with brachycephalic airway syndrome. Today’s Veterinary Practice. January/February 2014. todaysveterinarypractice.com
38. Schlicksup MD, Phillips I. An overview of brachycephalic obstructive airway syndrome. Today’s Veterinary Practice. April 2026. todaysveterinarypractice.com

Grading Schemes, Organizations and Costs

1. Orthopedic Foundation for Animals. Respiratory Function Grading Scheme (RFGS).
2. The Royal Kennel Club. Annual Health Report 2024: Respiratory Function Grading Scheme grades by breed (French Bulldog data to December 31, 2024). Checked October 2026.
3. AKC Canine Health Foundation. Grant 01056-A (principal investigator J. Hauptman, Michigan State University, 2008–2009), grant summary page on akcchf.org; no published paper listed.
4. Government of the Netherlands. News release on stricter breeding rules for short-muzzled dogs (Dutch government news), August 24, 2023.
5. Langford Vets (University of Bristol). BOAS Management owner information sheet (checked October 2026); fixed-price list, prices correct at April 1, 2025.
6. MetLife Pet Insurance. Pet Insurance for French Bulldogs: “Vet Costs for 5 Frenchie Conditions” table, average treatment cost $3,000–$5,000. Checked October 2026.
7. Centers for Disease Control and Prevention. Pet Food Safety (page last reviewed January 30, 2025).

Veterinarians Cited

1. Dr. Jean Dodds, Hemopet. OFA Licenses Health Screen for Brachycephalic Breeds, May 14, 2023 (cited as Hemopet, 2023); Breeding Brachycephalic Dogs and Cats, Part 1, March 11, 2022 (byline Hemopet); Breeding Brachycephalic Dogs and Cats, Part 2, March 18, 2022 (byline Hemopet); Pet Obesity, May 2, 2020.
2. Dr. Karen Shaw Becker. The Race Against Time to Save ‘Flat-Faced’ Pets, Bark & Whiskers, March 15, 2023 (updated August 15, 2024); Flat-Faced Dogs’ Health Issues, Bark & Whiskers, January 29, 2024; Groundbreaking Surgery Improves the Lives of Flat-Faced Dogs (interview with surgeon Dr. Boaz Man), Bark & Whiskers, October 17, 2023.
3. Dr. Judy Morgan, Naturally Healthy Pets. Dealing With Heat Stroke in Pets, July 29, 2021; Collapsing Trachea, February 1, 2021; Kennel Cough, September 12, 2018.
4. Dr. Peter Dobias (as of October 2026, his site sells a harness and supplements). article on the most common mistakes in choosing and raising a puppy (harness, not collar); Injuries Aren’t an Accident; Pure Bred Dogs May Be Facing a Catastrophe. peterdobias.com, undated; accessed October 2026.

Veterinarians are cited for their published work, not as endorsers of BestFrenchBulldog.com. This guide is educational and doesn’t replace your vet. If your Frenchie struggles to breathe, has blue or gray gums, collapses or can’t cool down, treat it as an emergency and call your vet or emergency clinic now.