If you own a short-nosed dog, or are considering getting one, there’s a good chance you will have heard about BOAS. Here, we’ll look at the condition, the causes and when surgery might be needed. We’ll also explore the surgery itself as well as the benefits (and risks) involved.

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What is BOAS?

BOAS (Brachycephalic Obstructive Airway Syndrome) is a term used to describe a combination of factors causing breathing difficulties in breeds of dog with shortened skull and muzzle. “Brachy” is from the Latin for short and “cephalic” pertaining to the head. Those most severely affected are French bulldogs, English bulldogs and pugs. 

How does it happen? 

The passage of air from the nose to the throat becomes turbulent and restricted due to an excessive amount of fleshy tissue (tonsils, soft palate) relative to the size of the skull. If you think about a Labrador’s head containing the same amount of soft tissue as a pug, you can see that there is much less space available to fit these structures within.

How do I know if my dog needs BOAS surgery?

The following signs are all potential indications that your dog may need BOAS surgery:

  • Have you noticed your dog getting out of breath and struggling to cope during exercise or in hot weather? 
  • Has your dog refused to go for walks or had episodes of collapse? 
  • Does your dog sleep with their head elevated on a cushion or with a toy in their mouth? 
  • Is your dog prone to vomiting? 
  • Do they struggle to eat and drop food or choke? 

If you have noticed any of these indicators, it is advisable to arrange an examination with your vet. They will assess the severity of the disease, its impact on your pet’s quality of life and can advise if surgery is an option.

What does BOAS surgery involve?

Surgery involves removing the excess tissue causing obstruction along the airway, thereby widening the passage for air flow with the aim of reducing the clinical signs.

The physical features that can be surgically treated are elongated and thickened soft palate, obstructed nostrils (stenotic nares) and enlarged tonsils (tonsil hypertrophy). 

The soft palate 

This is the mobile piece of flesh that dangles down at the back of the throat that separates the oral cavity from the nasal cavity. In brachycephalic breeds it is longer and thicker and can intermittently block the windpipe and briefly prevent breathing (apnoea), plus takes up more room in the throat, reducing the space for air flow. This structure is responsible for snoring. Surgery to correct this involves trimming it back to a more suitable length, like you would see in a long-nosed breed, or indeed in humans. 

Obstructed nostrils 

Common in some brachycephalics – in particular, pugs. Have you ever noticed they puff out their chests when breathing in? This increased effort is to overcome these narrow orifices to optimise the amount of air they can utilise with each breath. Surgery is aimed at removing the excess nasal tissue to open up the passage for flow of air. 

Enlarged tonsils 

Usually seen as a result of other airway issues. Over time, the tonsils become enlarged and are pulled out of their pockets due to a negative pressure created within the throat, further adding to turbulent air flow. Tonsils causing obstruction can be surgically removed.

Who does the surgery?

Your own vet may have the expertise and equipment to be able to carry out these procedures themselves. In some instances, they may arrange a referral to a soft tissue specialist. 

Some features of BOAS cannot be managed with surgery, such as a narrow windpipe. So it is important to discuss your dog’s individual case with your vet. If your dog is overweight, they may suggest a weight loss plan initially, because obesity plays a role in the severity of the symptoms.

Will it help my dog?

There is no doubt that BOAS impacts the quality of life of those affected: the feeling of struggling to breathe is as distressing for dogs as it is for humans. A state of stress further compounds breathing difficulties and a self-perpetuating cycle can quickly develop. 

Panting is a dog’s way of reducing temperature and therefore it is common for dogs with dysfunctioning airways to quickly overheat (hyperthermia).  Add to the mix a walk on a hot summer’s day, and these patients can also develop heatstroke, an emergency condition where sedatives and active cooling is needed to lower their temperature. Sadly, there are cases where this can rapidly lead to respiratory collapse and death.

BOAS can cause sleep disorders, the effects of which are only now becoming apparent. These patients wake up frequently while asleep due to the soft palate blocking the windpipe (apnoea). They tend to be excessively sleepy in the day and can fall asleep while sitting or standing. Lack of sleep, like in humans, weakens the immune system and makes individuals more prone to infection and chronic disease. 

In the best-case scenario surgery will improve breathing and reduce the chance of developing secondary complications, as well as improve the overall quality of life of these patients.

What are the risks with surgery?

All procedures that require general anaesthetic come with risk. In brachycephalic breeds this is a little higher due to the nature of their narrow airways and the swelling caused by surgical procedures. 

Your vet will have protocols in place to manage these risks effectively. This includes prescribing additional medications to reduce stress and acid reflux in the lead up to the surgery. They may also implement additional monitoring, especially in the recovery period. 

Due to the nature of the disease having not one, but multiple causes, it is not uncommon for follow up surgeries to be required, if the first procedure does not provide the desired results.

The surgery overall has been associated with a favourable outcome (50% of cases having a good-excellent outcome). Surgery is unlikely to resolve the breathing issues fully, but in the majority of cases it can reduce the clinical signs and improve the quality of life of your pet.

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