Brachycephalic Obstructive Airway Syndrome (BOAS) in dogs

BOAS is a condition that affects dogs with short, flat faces. Their snuffly breathing is often considered normal but is actually a sign that they are struggling to breathe.

BOAS stands for brachycephalic obstructive airway syndrome but can also be called brachycephalic respiratory syndrome. BOAS refers to a group of conditions caused by abnormalities in the body that can often result in breathing difficulties and other problems. Early diagnosis is extremely important. If your dog is showing signs of BOAS, it is best to discuss this with a vet as soon as possible.



What is BOAS in dogs?

BOAS is a combination of signs that impair breathing and is seen in flat-faced (brachycephalic) breeds.

BOAS is a lifelong, and often progressive disorder, meaning that it will get worse with time.

The physical changes seen in these dogs mostly affect the airflow through the upper airways. These include the nose, mouth, throat and windpipe.

The physical changes seen in dogs with brachycephalic syndrome are:

  • Narrowed nostrils
  • Compacted nasal cavities and a short nose
  • Overlong soft palate (which contributes to “snoring” noises when they breathe)
  • A tongue that is too big for their shortened head
  • A narrow trachea
  • Throat problems

It is possible for your pet to suffer from one or more of these problems, which can result in different degrees of obstruction.

BOAS in dogs 1
Narrow nostrils
BOAS in dogs 2
Crowded nose and throat
BOAS in dogs 3
Overlong soft palate
BOAS in dogs 4
Narrow windpipe


Due to these features, these dogs “pull” harder when they breathe in. This creates a strong negative pressure in their throats, necks, and chests. And this leads to additional respiratory and digestive problems, like vomiting.

Speak to a vet about your dog’s nose shape and discuss any symptoms. Early diagnosis has a big impact on your dog’s quality of life and life span.



Symptoms of BOAS in dogs

The signs of BOAS are varied and can range in severity, including some or all of the following:

  • Difficulty breathing
  • Loud, raspy respiratory sounds
  • Excessive panting
  • Snorting
  • Snoring
  • Coughing
  • Gagging or retching
  • Difficulty exercising
  • Collapse
  • Worsening signs in hot or humid weather
  • Vomiting and regurgitation



Are some dogs more at risk of BOAS than others?

Severe breathing problems can be life-threatening.

There are four main risk factors:

  • Brachycephalic breeds, including English and French Bulldogs, Boxers, Pugs, Shih-Tzus, Pekingese, Cavalier King Charles Spaniels, Dogue de Bordeaux, and Chow Chow.
  • The severity of the physical defects.
  • Being overweight or obese.
  • Older age.
Untitled design
Difference between the head shape of a “normal” dog (top) and a brachycephalic breed (bottom).



How will your vet know if your dog has BOAS?

Your vet will assess your dog’s facial shape and behaviour in certain circumstances. They will also carry out a physical examination and perform further investigation:

  • Visual inspection
  • Heavy sedation or full anaesthesia
  • Rhinoscopy
  • X-rays and/or CT scans


Vet treatment

Treatment options available for dogs with brachycephalic syndrome:

The main treatments include weight control and surgery.

Will your dog need BOAS surgery?

There is a good chance your flat-face dog has a degree of upper airway obstruction. Snoring noises are usually a sign of upper airway obstruction. The key is to decide if surgical correction will improve their quality of life.

Your veterinarian might recommend one or more of the following surgical procedures based on your dog’s specific needs. In some cases, referral to a specialist surgeon is recommended.

  • Widening of the nostrils
  • Reducing the length of the soft palate
  • Removing excessive and/or everted throat tissue

Even with surgery, brachycephalic animals’ airways will never be completely normal.

Are there any medical treatment options for dogs with BOAS?

  • Weight control
  • Medication to reduce inflammation
  • Treatment of any other related conditions, such as gastroesophageal reflux disease, pneumonia, and allergic diseases.


Home treatment

How to help your dog with BOAS at home?

There is a lot you can do at home to improve your dog’s health if they have BOAS, such as:

  • Keep your dog slim: Most flat-faced dog owners resign themselves to the fact that their dog is overweight. This mostly happens because of the breed’s tendency to gain weight due to their lifestyle. Being overweight isn’t normal for flat-faced dogs. Plus carrying extra weight will make any breathing problems worse.

The best way to assess your dog is to look at their body shape. Give your dog a “body condition score” using the body condition score chart. Vet nurses can help you to reduce your dog’s weight.

Body Condition Score (BCS) is a scale that gives a practical evaluation of the fat coverage of your dogs body. By checking how easy or not it is to feel certain bony areas of the body, a score is then produced. There are several scales, from 1 to 5 or 1 to 9. The ideal body condition lies in the middle, so either 3/5 or 5/9.

The body areas normally checked for fat coverage are:

1. ribs and spine

2. hips and shoulders

3. waist

Body condition scoring (BCS) in dogs

Here are a few tips on how to do it.

With your pet in a standing position:

  • Place your hands on the rib cage and gently feel for each rib, without pressing too hard
  • Feel the waist and look from the top and the side (if you have a very furry breed, it may be harder to assess)
  • Feel the spine, which runs down the middle of the back
  • Feel the top of the hips and shoulders


  • Keep them fit: Keep your dog as fit as possible and build their fitness gradually. Flat-faced dogs often struggle to keep up with other breeds.
  • Use a harness: Instead of a collar to minimise pressure on the neck.
  • During hot/humid weather: Keep your dog indoors, preferably with air conditioning, and limit exercise.
  • Reduce any respiratory irritants in the home: Such as smoke, dust, or mould.
  • When sleeping: Brachycephalic dogs may find it difficult to sleep.  They often snore while sleeping and wake up for brief periods when their breathing stops. You can try to raise their head up to keep their airway open when sleeping to improve their quality of sleep.



How can you prevent and minimise the signs of BOAS in dogs?

Responsible breeding: dogs with significant breathing difficulties or that need surgery should not be used for breeding. It is usually recommended that these animals be neutered at the same time surgical correction is performed.

Ongoing care: to reduce the severity and frequency of BOAS symptoms follow the previous recommendations on diet, exercise, and environmental modifications.


What to expect if your dog has BOAS

What is the overall outlook for a dog with BOAS? 

The prognosis for dogs with BOAS depends on how many physical problems are present and how old your dog is at the time of diagnosis and treatment.

To maintain quality of life, vet visits should be done regularly to monitor new symptoms or to see if any worsen.


What age do dogs get BOAS?

BOAS usually presents in dogs between 1-4 years of age but severe cases may be noted at only a few months of age.


What age should dogs have BOAS surgery?

It is usually recommended to wait until 9 months to 1 year of age to perform surgery.


How much does BOAS surgery cost for dogs?

BOAS surgery can be expensive, especially if more than one aspect needs to be corrected.

Consider getting your dog insured as soon as you get them, before any illness develops. Look carefully as not all insurance policies cover BOAS problems.

Try to speak openly to your vet about any treatment cost concerns, along with what you think is right for your dog.

Often, there are multiple treatment options, so if one doesn’t work for you and your pet, then your vet may be able to offer an alternative.


What other diseases are associated with flat-faced breeds? 

Nasal fold dermatitis: Skin folds can become infected due to heat and moisture. Keep these areas clean and dry to prevent infection.

Gastric and oesophageal reflux: Giving specific foods and feeding in a certain way can be helpful for these dogs.  Speak to a vet for further information.

Eye problems: The large and protruding eyes of these dogs mean that their eyelids cannot close fully. This dries the eyes and often leads to eye ulcers and excessive tearing.


When to worry

When to worry if your dog has BOAS?

Seek immediate assistance from an emergency vet practice if your dog:

  • Struggles to breathe or gasps for air
  • Gums or tongue become blue or grey
  • Collapses

At Joii we can help:

  • Advise about getting a flat-faced breed dog
  • Assess your dog’s condition or help them lose weight
  • Build up their fitness gradually
  • Check if your dog has any symptoms of BOAS


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