Brachycephalic Airway Syndrome in Dogs

Category: Airway & Lung
Inheritance: Multifactorial
Breeds documented: 18
Published sources: 13

Overview

Flat-faced dogs can have airways that are too cramped for easy breathing. Brachycephalic airway syndrome, also called BOAS, involves blockages caused by features such as narrow nostrils and excess throat tissue. Some dogs also have a windpipe that is too narrow. The condition can limit exercise and make swallowing harder. Repeated strain from trying to breathe can cause swelling and further blockage, so the problem may worsen over time.

Signs to watch for

Loud snoring, snorting, or wheezing
Breathing that looks difficult or takes extra effort
Struggling to keep up during exercise
Gagging while eating or drinking
Blue-tinged gums or tongue
Fainting or collapsing

Breathing problems can occur in puppies younger than six months.

Emergency Go to an emergency vet immediately for severe breathing difficulty, blue gums or tongue, or collapse.

Diagnosis and tests

A vet considers the dog's breathing history, head shape, and physical examination. Narrow nostrils are visible, but the dog needs to be asleep under anesthesia for the vet to examine deeper throat tissues. Neck and chest X-rays help assess the windpipe, and the vet may also examine the airway with a camera.

Breeds with documented risk

18 breeds

By breed size

4 Toy
11 Small
2 Medium
1 Giant

All 18 breeds, A to Z

Affenpinscher

Boston Terrier Sources journals.plos.org onlinelibrary.wiley.com
Brussels Griffon Source journals.plos.org
Bulldog Sources doi.org link.springer.com onlinelibrary.wiley.com

Chug Source petmd.com

Dogue De Bordeaux Source journals.plos.org

English Toy Spaniel Source journals.plos.org

French Bulldog Sources link.springer.com onlinelibrary.wiley.com

German Spitz Source onlinelibrary.wiley.com

Japanese Chin Source journals.plos.org

Keeshond

Lhasa Apso

Malshi Source petmd.com

Pekingese Sources journals.plos.org onlinelibrary.wiley.com
Pomeranian Source onlinelibrary.wiley.com
Pug Sources link.springer.com onlinelibrary.wiley.com
Puggle Source petmd.com

Shih Tzu Source journals.plos.org

Inheritance

Multifactorial
Several genes and the environment together set the risk. Diet, growth rate, weight and exercise can all play a part. There is no single DNA test. Screening the parents (for example hip or elbow scores) and choosing from lines with good results lowers the risk, but does not remove it.
As stated by OMIA

We've gathered what published sources say about this condition, so you can talk it through with your vet. It isn't veterinary advice: you and your vet know your dog best.