Referral, assessment and guidance on patients with BOAS symptoms

Brachycephalic Obstructive Airway Syndrome

Brachycephalic obstructive airway syndrome (BOAS) is often seen in brachycephalic dog breeds (breeds that have a shorter and wider muzzle length in comparison to the skull as a whole). Breeds like Pugs, French Bulldogs and Bulldogs are commonly seen with this condition. This skull conformation creates an excess of soft tissues in the upper airways which then obstructs the air flow and forces the animal to rely on open mouth breathing.

Primarily, it is a combination of different structures of the upper airway that are affected, including:

  •  nostrils
  • nasal turbinates
  • tonsils
  • soft palate
  • larynx/laryngeal saccules

Occasionally, the affected dog may also have a hypoplastic (smaller sized) trachea.

The increased resistance to airflow through the upper airway is caused by the space being taken up by these tissues, and the dog will need to make extra effort to take in breaths.

This is demonstrated by very loud snoring when asleep, or some dogs may snore even when awake or at rest. Sometimes, these dogs will sleep with a toy wedged into their mouths, or rest their head on an elevated surface. When they exercise, they pant continuously or have difficulty exercising in warm weather. They often pant for a long time after exercise, as they can’t easily cool down. Some dogs will collapse when they exercise or get excited, and may become so breathless that they lose consciousness. As dogs have to pant to cool down affected dogs are more prone to heat stroke.

All brachycephalic dogs are affected to an extent with this syndrome. Dogs that are not severely affected may cope well as long as they don’t become overweight and are never exercised in warm weather. If further airflow resistance develops long-term the dog may develop laryngeal collapse due to the pressure on the larynx (voicebox). When this happens, the airflow resistance becomes very much worse and can be very difficult to treat. The aims of BOAS surgery is to reduce airflow resistance in the upper airways and prevent longer term deterioration of the airway structures.

At DentalVets, we perform surgery to widen the nostrils and to shorten the soft palate to an anatomically correct position. Sometimes we need to remove the tonsils to open up the airway. Treatment for laryngeal collapse or removal of hypertrophic turbinates is usually delayed to see if the dog improves after BOAS surgery. Treatments for laryngeal collapse and turbinates are very advanced and carries high morbidity rates. Because of this, these procedures are not offered here.

The dogs are discharged the same day with pain relief, anti-inflammatories and occasionally antibiotics. In rare circumstances, some dogs can panic after surgery due to the swelling and discomfort. These cases may be monitored out-of-hours here at DentalVets overnight, where they may need a temporary breathing tube inserted into their trachea to help them breathe until they are calm and relaxed.

Strict rest at home is required for 7-10 days post operatively but thereafter the dogs can be treated normally. Some dogs may require treatment for pre-existing aspiration pneumonia, if there is a history of respiratory infection. Most of the dogs will improve after surgery, but some may require a course of antacid medication whilst they recover.

BOAS Information Document