The snoring and snorting most owners treat as Shih Tzu character are signs of brachycephalic obstructive airway syndrome (BOAS) — a structural narrowing of the airway caused by the breed’s flat face. The honest picture is reassuring and serious at once: Shih Tzu are affected far less severely than Pugs or French Bulldogs, but a 2026 study of 898 dogs found only 25–50% of Shih Tzu completely unaffected. The one risk factor you fully control is weight, and in Shih Tzu specifically, being overweight carried five times the odds of BOAS.
What BOAS Actually Is
Selective breeding shortened the Shih Tzu’s skull. It did not shorten the soft tissue inside it. The result is a normal quantity of tongue, soft palate and throat tissue packed into a much smaller space — like closing a suitcase that was packed for a larger one.
The syndrome has several components, which occur in combination and to varying degrees:
- Stenotic nares — nostrils too narrow, sometimes collapsing inward on each breath
- Elongated soft palate — excess tissue at the back of the mouth partly blocking the airway
- Everted laryngeal saccules — tissue near the vocal cords drawn into the airway by the effort of breathing
- Hypoplastic trachea — a windpipe narrow for the dog’s size
- Laryngeal collapse — the voice box weakening over years of strain; this one is *progressive*, and it is why waiting is costly
BOAS is a spectrum, not a yes-or-no diagnosis. Most affected dogs sit somewhere in the middle.
How Badly Are Shih Tzu Affected?
This is where most breed content is either alarmist or dismissive. The data allows something better.
A 2026 study in *PLOS One* by Tomlinson, Liu, Sargan and Ladlow assessed 898 dogs across 14 brachycephalic breeds and graded them for BOAS. Grade 0 means unaffected.
| Breed | Graded unaffected |
| Pug | 7% |
| French Bulldog | 10% |
| Bulldog | 10.9% |
| Pekingese | 10.9% |
| Shih Tzu | 25–50% |
So a Shih Tzu is meaningfully better off than the breeds that dominate the headlines. It is also true that somewhere between half and three-quarters of Shih Tzu showed *some* degree of BOAS.
The useful conclusion is not “Shih Tzu are fine.” It is that this breed sits in the range where management genuinely changes outcomes — unlike the most extreme breeds, where the anatomy itself is often the limit.
The Signs Owners Normalise
Almost every sign of BOAS gets reclassified as personality. Watch for:
- Snoring, snorting or audible breathing at rest, not just after exercise
- Open-mouth breathing when the dog is not hot or exercising
- Stopping on walks, lying down mid-walk, or refusing to continue
- Sleeping with the head propped up, or in odd positions that open the airway
- Gagging, retching or bringing food back up — BOAS is strongly associated with reflux and gastrointestinal signs, and these frequently improve after airway surgery
- Recovery that takes a long time after mild exertion
Emergency signs — go to a vet immediately: blue, grey or very pale gums, collapse, or frantic breathing that does not settle.
A dog that snores loudly every night is not a dog with a charming quirk. It is a dog working hard to breathe while asleep.
Weight: The One Lever You Fully Control
If you read nothing else, read this.
In the same 2026 study, being overweight raised BOAS odds across all breeds (OR 1.8). But in the Shih Tzu-specific model, a higher body condition score carried an odds ratio of 5.0 — five times the odds of BOAS.
Fat deposits around the neck and throat compress an airway that is already short of room. A Shih Tzu carrying an extra kilogram is not slightly heavier; it is breathing through a narrower tube, every minute of every day.
The test is simple: run your hands along the ribs. You should feel them easily under a thin layer, without pressing. If you cannot, your dog’s breathing will improve measurably with weight loss — and this costs nothing.
Look At Your Dog’s Nostrils
Nostril stenosis was the strongest conformational predictor in the study: moderate stenosis carried an odds ratio of 4.2, severe stenosis an odds ratio of 10.
Go and look now. Open, oval nostrils are what you want. Narrow slits, or nostrils that pinch shut when the dog inhales, indicate stenosis — and this is the most straightforwardly correctable part of the whole syndrome. Widening the nostrils is a comparatively minor procedure with disproportionate benefit.
Heat Is the Acute Danger in India
A dog cools itself almost entirely by panting, which means moving air fast across a wet airway. BOAS makes that mechanism less efficient exactly when it is needed most.
A VetCompass study of 905,543 UK dogs (Hall et al., 2020) found brachycephalic dogs had 2.10 times the odds of heat-related illness, and that dogs at or above their breed’s mean bodyweight had 1.42 times the odds. The case fatality rate for heat-related illness was 14.18% — roughly one in seven affected dogs died.
That research was conducted in Britain. Apply it to a Delhi NCR summer and the practical rules are not optional:
- Walk before sunrise and after sunset. Nothing in the middle of the day, ever
- Reliable cooling indoors through peak summer, not just a fan
- Never leave a Shih Tzu in a parked car or on a closed balcony, even briefly
- Humidity compounds the risk, so monsoon afternoons deserve the same caution as May
- Panting that does not settle within a few minutes of rest and shade is an emergency
What a Vet Can Do
Examination and grading come first. Assessing the soft palate and laryngeal saccules requires light anaesthesia; X-rays measure the trachea; CT or endoscopy is available for detailed assessment.
Surgery can widen stenotic nares, shorten an elongated soft palate and remove everted saccules. A hypoplastic trachea cannot be corrected.
Timing matters more than most owners realise. Most dogs are diagnosed between one and four years old, dogs operated on before two do better, and dogs that have progressed to laryngeal collapse have poorer outcomes with or without surgery. The damage accumulates while you wait for it to get bad enough to act on.
If You Are Buying a Shih Tzu Puppy
Watch the parent dogs breathe while they are resting and quiet. Noise at rest in an adult is the clearest warning you will get.
Look for open nostrils and a visible muzzle — a more extreme flat face was associated with higher BOAS risk in the research. And understand that affected dogs should not be bred at all: this is a heritable conformational problem, not bad luck.
The UK’s Respiratory Function Grading Scheme, which formally grades breeding dogs, is not generally available in India. That makes your own observation of the parents more important here, not less.
Living Well With It Day to Day
Walk on a harness, never a neck collar — pressure on the throat of a compromised airway is exactly the wrong thing. Keep the dog lean. Walk in cool hours. Keep excitement from spiking in hot weather. Ask for a weight check at every single vet visit, and treat an upward trend as a respiratory issue rather than a cosmetic one.
Frequently Asked Questions
Is snoring normal for a Shih Tzu?
It is common, but it is not healthy. Snoring and snorting indicate partial airway obstruction. Occasional light snoring in deep sleep is usually mild; noisy breathing while awake and at rest warrants a vet assessment.
Do all Shih Tzus have breathing problems?
No. A 2026 study of 898 brachycephalic dogs found 25–50% of Shih Tzu completely unaffected — far better than Pugs at 7% — but it means most have some degree of BOAS.
Can brachycephalic syndrome be cured?
Not cured, but substantially improved. Surgery can widen nostrils, shorten the soft palate and remove everted saccules. A narrow trachea cannot be corrected, and earlier surgery gives better results.
Is a Shih Tzu safe in Indian summers?
With management, yes. Brachycephalic dogs have about twice the odds of heat-related illness, so walks must be early or late, indoor cooling is essential, and the dog should never be left in a car or on a closed balcony.
When should I take my Shih Tzu to a vet about breathing?
Any noisy breathing at rest, exercise intolerance, gagging or regurgitation, or sleep disruption. Go immediately for blue or pale gums, collapse, or breathing distress that does not settle.
Breathing Should Be Quiet
At The Barking Babies, we have placed puppies with over 15,000 Indian families since 2001, and we would rather you knew this before you chose a flat-faced breed than afterwards. A Shih Tzu is not a Pug — the research is clear that this breed sits in a far more manageable range — but “manageable” means something is being managed. Keep the dog lean, keep it cool, and treat noisy breathing as information rather than character.
