BOAS grading

We offer BOAS grading

Does your dog have abnormal breathing sounds, decreased stamina or panting more than expected? A-Vet offers BOAS grading based on the Norwegian Kennel Club's screening program.

What is BOAS Grading?

BOAS (Brachycephalic Obstructive Airway Syndrome) is a collective term for respiratory disorders that can affect short-nosed, brachycephalic dogs. The condition is caused by anatomical conditions that result in reduced air passage through the upper airways. Symptoms can range from abnormal breath sounds and snoring to pronounced breathing difficulties, reduced exercise tolerance and, in severe cases, collapse or loss of consciousness.

The Norwegian Pug Club and the Norwegian Bulldog Club, in collaboration with the Norwegian Kennel Club, have established a screening program for BOAS. The grading method was developed through research at the University of Cambridge and provides a standardized assessment of the dog's respiratory function.

NKK's Norwegian screening program includes pugs, French bulldogs and English bulldogs.

What other dog breeds can be affected by BOAS?

However, BOAS can occur in more brachycephalic breeds than the three included in the NKK's Norwegian screening program. In 2026, the RFG (Respiratory Function Grading) form was opened for use on 14 new breeds. The purpose is, among other things, to examine more dogs and gather knowledge that can contribute to more knowledge-based breeding. For these breeds, this is not currently the same as a requirement for BOAS grading for breeding or participation in exhibitions. The breeds for which the RFG form is now open are:

• affenpinscher
• Boston terrier
• Boxer
• cavalier king charles spaniel
• Chihuahua
• Mastiff of Bordeaux
• Brussels Griffon
• Japanese Chin
• King Charles Spaniel
• Maltese
• Pekingese
• Pomeranian
• Shih Tzu
• Staffordshire bull terrier

Anatomical changes such as narrow nostrils, thickened or elongated soft palate, narrow conditions in the pharynx, and secondary changes in the larynx can contribute to reduced air passage.

Who can grade?

Only veterinarians who have completed NKK's BOAS grading course can issue official BOAS certificates and register the results in DogWeb. At A-Vet, Elisabeth Bjørnestad is an approved BOAS veterinarian. The dog must be at least 18 months old at the time of grading, and the certificate is valid for two years.

Symptoms of BOAS

Abnormal breath sounds and reduced respiratory function should not be considered normal just because the dog has a short snout. Symptoms of BOAS usually appear at 2-3 years of age, but may appear later in some dogs and may gradually worsen throughout life. Signs of BOAS may include:

• Snoring, wheezing, or other obvious breathing sounds while awake.
• Labored breathing or clearly increased work of breathing.
• Narrow or constricted nostrils.
• Reduced exercise tolerance or the dog having to quickly stop during activity.
• Heat intolerance and abnormally heavy panting in hot weather.
• Sleep problems, snoring or stopping breathing during sleep.
• Regurgitation, vomiting or other gastrointestinal symptoms.
• Bluish discoloration of mucous membranes (cyanosis), collapse or loss of consciousness (syncope) in severe airway obstruction.

How is the BOAS grading done?

In BOAS grading, the dog's respiratory sounds and work of breathing are assessed both before and immediately after a standardized exercise test. The exercise test consists of three minutes of trotting at 6–8 km/h. The veterinarian observes the dog's breathing and listens to the airways, and the results are used to classify respiratory function according to the NKK's fixed grading scale:

• Grade 0: Clinically unremarkable. No respiratory symptoms.
• Grade I: Clinically unremarkable. Mild BOAS symptoms from the respiratory tract, but do not affect activity.
• Grade II: Clinically affected, and should not be used for breeding. The dog has moderate respiratory symptoms, and these should be monitored. The dog may require treatment, including weight reduction and surgery.
• Grade III: Clinically affected, and should not be used for breeding. The dog has serious signs of respiratory tract disease as a result of BOAS and should be thoroughly examined by a veterinarian and treated.

Dogs that have been operated on for BOAS automatically receive grade III and should not be used in breeding.

What can the owner do himself?

Being overweight can worsen BOAS and make breathing more difficult. It is therefore important to keep your dog slim and in good physical shape. Avoid strenuous activity in hot weather, and pay special attention to signs of overheating.

If your dog has difficulty breathing, reduced exercise tolerance, or other signs of BOAS, they should be examined by a veterinarian. In cases of clinically significant airway problems, surgical treatment may be considered. The need is assessed based on the dog's symptoms, anatomical conditions, and the degree of airway obstruction.

Many dogs experience significantly improved respiratory function and quality of life after surgical treatment, but the outcome depends on factors such as the anatomical changes present and the severity of the disease. Weight reduction can also be an important part of treatment in overweight dogs. In NKK's website you can read more about BOAS grading.

Price of BOAS grading and BOAS surgery

See our prices for BOAS grading, or contact us if you would like information about surgical treatment. Surgeries are priced according to, among other things, the type of procedure, method, extent and medication consumption.