Brachycephalic Airway Obstruction Syndrome (BAOS) in Boston Terriers is reader-supported. If you buy a product through a link on our site, we may earn an affiliate commission at no additional cost to you.

Brachycephalic airway obstruction syndrome (BAOS) is a genetically transferred and breed-specific set of abnormalities that affect the upper respiratory systems of affected dogs, causing breathing difficulties.

The Boston Terrier has a flat face, which makes it adorable and gives a graceful look, but because of its shorter snout, it’s prone to brachycephalic airway obstruction syndrome. This syndrome affects almost all Boston Terriers to some degree, causing snoring, coughing, panting, noisy breathing, and exercise intolerance.

It is essential to keep an eye on your dog and look for signs because if your Boston is struggling to breathe and collapsing, you must consider it a medical emergency that can be fatal. This article will help you understand this condition better. Let’s start.

Brachycephalic Airway Obstruction Syndrome (BAOS) in Boston Terriers

Brachycephalic Breeds

Brachycephaly is derived from Greek words meaning “short-head.” It refers to a skull deformity in dogs that have shorter-than-normal snouts or a lower length-to-width ratio of the skull. Brachycephalic breeds were favored for bull baiting because this feature provided them with a better, stronger bite.

Brachycephalic breeds have a flat-faced appearance, giving them more human-like looks, which are liked by dog owners. Here are some famous brachycephalic dog breeds:

  • Bulldog
  • Pug
  • Boxer
  • Boston Terrier
  • Lhasa Apso
  • Pekingese
  • Bullmastiff

What Is Brachycephalic Airway Syndrome?

The brachycephalic breeds were developed by breeders by means of artificial selection to increase the short snout feature of these dogs. So, these dogs are not a result of the survival of the fittest procedure of nature and have problems because of being more sensitive than normal dogs.

Their short skull has decreased skeletal growth, but now their soft tissue mass is the same as of any non-brachycephalic breed dog. It means that now a larger mass has to adjust in a shorter space. This puts pressure on the respiratory system causing difficulty in breathing.

Symptoms Of BAOS

Brachycephalic airway obstruction syndrome, or BAOS, affects almost all brachycephalic dogs. However, some dogs are more affected than others. The dogs that appear clinically normal are also under respiratory stress but not to a degree to cause the clinical symptoms.

These dogs may also show symptoms when under heat stress or performing rigorous exercises. BAOS is characterized by the following signs:

  • Snoring
  • Noisy breathing
  • Coughing
  • Exercise intolerance
  • Gagging
  • Collapse
  • Difficulty in breathing
  • Vomiting

Other Problems Associated With BAOS

BAOS is present in varying degrees in almost all Boston Terriers.

Brachycephalic airway obstruction syndrome is an anatomic problem (related to the skeleton). It’s genetically passed on and may cause lung anomalies, windpipe, and stomach issues.

The competition for space among different structures in the face region leads to the weakening of some parts, which causes health problems.  These health issues include:

Dental Problems

The upper jaw of these dogs is shorter but still contains the same number of teeth as any other non-brachycephalic breed, which increases the competition for space. Teeth have less space between them which causes the tartar to build up easily and cause dental problems.

Brachycephalic Ocular Syndrome

Brachycephalic breeds have large eyes which are protruded outwards. The eyelids may not be able to cover the eyeball properly. This is necessary to keep the surface of the eye moist. Hence, the resulting dehydration of the eyes can cause ulcers and eye infections in these dogs.

Skin Infections

The folded facial skin can harbor harmful bacteria, and improper cleaning can cause these infections to grow unnoticed. That’s why Boston Terriers require intensive skin care to avoid such mishappenings.

It is important to note that being on the lookout for such signs and heeding them when such issues are starting can pay off in terms of the good health of your furry friend without requiring extensive medical intervention. As the saying goes, “A stitch in time saves nine.”

Diagnosis Of BAOS

The diagnosis is based on physical examination and radio-diagnostic testing such as X-rays and CT scans. In the physical examination, the history of the dog is taken, signs and symptoms are noted, and an examination of the oral cavity is done to determine the cause.

While radio diagnostics can provide the anomalies of physically inaccessible structures such as lungs, windpipe, bronchi, etc. These imaging techniques allow the veterinarian to get a closer look at the dog’s airway and identify any obstructions or abnormalities.

A knowledgeable veterinarian, with the help of these techniques, will be able to diagnose what is causing issues in your furry friend.

Treatment Of BAOS

This syndrome is present in varying degrees in almost all Boston Terriers. It may be severe in some and non-clinical (showing no signs) in others. The treatment options because of that can differ widely. It is resolved in some dogs by mere better management that addresses the specific needs of your dog.

By effective weight management and limiting the exercise of your Boston Terrier, you can lessen the severity of the condition. Excessive weight can lead to increased oxygen requirement, which can cause the severity of the condition. Using specific collars designed for brachycephalic breeds can also help relieve the pressure.

Brachycephalic dogs have different requirements than other dogs. Proper management and exercise restrictions according to breed requirements, along with medications like corticosteroids and anti-inflammatory drugs, can help resolve most cases.

Surgical Treatment Options

If the extent of the syndrome is severe and the severity of the condition does not decrease or respond to non-surgical methods and management, you may have to go for surgical correction to relieve your Boston Terrier’s condition.

With the help of radiographs and examination, your veterinarian will find out the root cause that is obstructing or narrowing the airway and, with surgical methods, resolve that issue. These are some surgeries that your vet may recommend.

Soft Palate Resection

In this surgery, the excessive soft palate, which is the tissue of the upper jaw in the mouth above the tongue, is removed if it is blocking the proper breathing of your dog.

Stenotic Nares Correction

The nares (external openings of nostrils) are sometimes covered with an excessive fold of skin. These flaps cause obstruction in breathing by narrowing the openings. They are surgically corrected to provide optimum openings for your dog to breathe easily.

Laryngeal Saccule Excision

It is a surgical procedure to open the airway at the larynx if it is narrow and the dog has difficulty breathing. These surgical procedures, when conducted by a skilled veterinary surgeon who has experience with this syndrome, greatly improve the quality of life and resolve this condition in dogs suffering from BAOS.

Prognosis For Dogs With BAOS

The prognosis can range from very good to poor depending upon the condition, severity, and anatomical structures involved in causing the infection. Age also plays an important factor. Dogs under two years old, when corrective surgeries are performed, have a better prognosis than older dogs.

The dogs that require minimum intervention, like stenotic nares correction, also have a good prognosis. The cases with hypoplastic trachea or when there is the development of secondary conditions due to BAOS have a poor prognosis.


Brachycephalic airway obstruction syndrome (0BAOS) is a common health issue in Boston Terriers that comes at the expense of their fabulous looks. It causes breathing abnormalities and, if left untreated, can cause secondary health concerns. Luckily, treatment options are available to manage symptoms and improve your dog’s quality of life.

If you suspect your Boston Terrier may have BAOS, seek veterinary care promptly to prevent the condition from worsening. Proper management and care can help your dog live a happy and healthy life.

Dr. Majid Tanveer, DVM

Dr. Majid Tanveer is a graduate of Islamia University with a Doctorate in Veterinary Medicine. Dr. Majid has worked extensively for the betterment of animal welfare in his country of Pakistan, where he lives with his Boston Terrier and works as a senior veterinarian.

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