Brachycephalic Obstructive Airway Syndrome (BOAS) is a condition affecting dogs with short, flat faces,. It’s caused by anatomical abnormalities and respiratory function that obstruct the airways, making breathing difficult and affecting the dog’s quality of life.

OFA has listed three breeds affected: Bulldogs, French Bulldogs, and Pugs. BOAS is caused when the soft tissue in the nose and throat is excessive for the airway, partially obstructing the airway and making it difficult for them to breathe normally.

It is more than a conformation issue (physical issue) because it is when respiratory function is affected. This would present as follows:

• Ability to walk, run, play is impaired because the dog cannot get enough air in
• The dog may snore more and wake up more often as they sleep
• The dog may easily overheat
• Your dog may have foam coming out of their nose when they exercise
• The dog may regurgitate their food
• The dog may have difficulty swallowing

The following section is taken from OFA’s website:

In an effort to learn more about the condition, increase awareness, and ultimately reduce the incidence of BOAS, researchers at the University of Cambridge in the UK developed the Respiratory Function Grading Scheme (RFGS). The goal of the RFGS was to develop an objective test to measure the clinical diagnosis and severity of BOAS.

The exam is conducted by a specially trained and approved veterinarian and consists of 4 steps:

1. A short health survey regarding the dog’s breathing history.
2. A brief physical exam while the dog is calm including auscultation where the assessor listens to the dog’s breathing with a stethoscope gently positioned on the side of the neck. This establishes a baseline for the absence of or severity of any clinic signs of BOAS.
3. A brief exercise test consisting of a brisk three minute walk. This is designed to expose clinical signs of the disease in an otherwise calm and asymptomatic dog. It is not designed to assess cardiovascular fitness.
4. A post exercise auscultation after increased airway activity to compare to the pre-exercise baseline.

The noises the trained veterinary assessors are listening for during auscultation include:

• Stertor – a low pitched vibrational noise heard above the level of the larynx
• Stridor – a higher pitched ‘sawing’ noise heard over the larynx
• Nasal Stertor – a low pitched nasal snort/vibration
• Nasal Stridor – a higher pitched nasal/whistle, usually heard on breathing in

The Respiratory Function Grading Scheme assigns a sliding scale of 0 to 3 to objectively diagnose BOAS:

• Grade 0:  The dog is clinically unaffected and free of any respiratory signs of BOAS (no evidence of disease, no BOAS related noise heard even with a stethoscope)
• Grade I:  The dog is clinically unaffected but does have mild respiratory signs linked to BOAS (noise is mild and only audible with a stethoscope)
• Grade II:  The dog is clinically affected and has moderate respiratory signs of BOAS (noise is audible even without a stethoscope)
• Grade III:  The dog is clinically affected and has severe respiratory signs of BOAS (noise is audible even without a stethoscope)

*** NOTE – If a dog exhibits respiratory difficulty, cyanosis or dyspnoea, it is not necessary or advisable to conduct the exercise test as these dogs are already in the Grade III range.

Both Grade 0 and Grade I are considered to be clinically BOAS unaffected as they exercise without difficulty and do not appear to have any clinical signs related to airway obstruction.

In Grades II and III, when stertor or stridor noise is heard without a stethoscope, whether intermittent or continuous, these dogs are considered clinically affected with clinical signs affecting quality of life. These dogs should be monitored and may require veterinary treatment.

Using the RFGS grades and the guidelines in the chart below, concerned responsible breeders can apply the selective genetic pressure to reduce the chances of producing puppies affected by BOAS. However, since the inheritance of BOAS is not fully understood and is not entirely predictable, this guidance cannot guarantee that all puppies from unaffected parents will be free of BOAS.

Your Vet Can Asses Your Dog

Your vet can conduct this same test for your dog. They will need to send the completed forms certifying your dog cleared their tests to OFA.

Don’t Rush Into Surgery

You may encounter a vet who recommends that your dog’s nares be widened. There are a few things to keep in mind.

• Did your vet also inspect your dog’s respiratory function?
• Did your dog look to see if your dog has an elongated palette because a cosmetic surgery that ignores if there is an elongated palate may not resolve the symptoms you might be trying to correct.
• Does your vet have experience conducting surgery on Boston Terriers?
• Is the quality of your dog’s life affected? Or is this just a cosmetic surgery?

Remember any surgery provides risks and working with a vet who is well versed in respiratory function and conformation is preferred and recommended.

Sometimes scar tissue may form as a result of the surgery and make matters worse so surgery does not always guarantee results.

Advocating For Responsible Breeding Practices

The Boston Terrier Club of San Diego advocates for responsible breeding practices. This means breeders regularly screen for any health issues and do not breed dogs that will pass on disorders. We also actively educate the community at large in our efforts to educate you as a prospective buyer to support breeders of healthy Boston Terriers.