Five more frequently asked questions about BOAS or brachycephalic obstructive airway syndrome in dog

Brachycephalic dog breeds like the French bulldog, English bulldog and Shih Tzu are really popular in the UK today, and are a hugely common sight on the streets and in the dog parks all over the country.

Dogs with flattened-looking faces like these – which is a simple description of the physical appearance of a brachycephalic dog – are present in much larger numbers these days than they were historically, and breeds of these types are in great demand among puppy buyers.

However, many prospective buyers of brachycephalic dogs don’t realise that those flat faces come at a cost – and which can have a significant impact on the quality of life and general wellness of dogs that possess it. BOAS or brachycephalic obstructive airway syndrome is the name given to a collection of breathing and respiratory system problems that dogs with very flat faces can possess.

A great many brachycephalic dogs whose faces are only moderately flat are robust and healthy and lead perfectly normal lives, but dogs that are bred for highly exaggerated and overly flat faces, which is sadly very fashionable in some breeds, often have a number of complex health issues as a result of this, falling under the heading of BOAS.

Breeders of brachycephalic dogs with very exaggerated features rarely ensure that puppy buyers understand the implications of such features – as this might affect their chances of a sale – and will even in some cases claim that such features demonstrate excellent quality and desirable traits within the breed, as opposed to instead increasing the risk of BOAS.

This means that there is a lot of conflicting information around and prospective puppy buyers considering brachycephalic breeds often make poor or uninformed decisions as a result of this. To assist prospective buyers of brachycephalic dogs, this article will share the answers to five more frequently asked questions about BOAS in brachycephalic dogs. Also, check out our five initial BOAS FAQ article, and our five frequently asked questions about caring for a dog with BOAS too.

What causes BOAS to develop in dogs in the first place?

BOAS isn’t a condition that is caught or transmitted, and it develops as a direct result of a number of conformation defects that dogs with flat faces can possess. The trait of being brachycephalic isn’t a norm for the canine species, and in the wild, dogs with very flat exaggerated faces simply wouldn’t survive, and it is only selective breeding by humans that maintains and increases the trait in the domestic dog population.

BOAS is hereditary in so much as that the physical traits of a parent tend be transferred to their young (particularly if possessed by both parents) and so a parent with the type of conformation that causes BOAS is highly likely to pass a similar conformation onto their offspring.

Ultimately, BOAS is caused by a number of conformation defects present in dogs with exaggerated brachycephalic faces.

What conformation features result in BOAS?

The physical features that result in BOAS can vary, as BOAS is a collection of conditions that are in turn caused by a collection of problems. Some affected dogs may display several such traits and conditions combined, others just one.

The conformation features that result in some of the conditions that fall under the heading of BOAS are:

• The dog’s soft palate (the roof and back of the mouth) being elongated compared to the norms for the species, and also, thicker than normal.
• The dog’s nostrils being very narrow (this is known as stenotic nares) and often, so small as to look pinched closed, so that the dog struggles to inhale enough air.
• Windpipe or tracheal defects that result from the flat face and head shape.
• Laryngeal saccules within the trachea, which means growths that obstruct the free flow of air through the dog’s windpipe.

Can you tell if a dog has BOAS just by looking at them?

As you can probably tell from the above question and answer, not all of the conformation factors that result in BOAS will be obvious simply by looking at the dog, because you can’t see into their windpipe or soft palate!

However, if a dog has very small, pinched or closed-looking nostrils, this is something you can tell by observation, particularly if you can compare these to the nostrils of a normal dog for perspective.

If a dog’s face is very flat – viewed side-on, their nose protrudes barely, if at all – they will also have a long and thick soft palate, and so this is something you can see as well.

Additionally, if a dog has a very short, flat face, their tongue will be too long for their mouth and will often protrude or hang out a long way.

These are just some of the ways that someone with an attuned eye can assess the chances of a brachycephalic dog being likely to have BOAS, and to what extent – the more extreme the above exaggerations, the worse the BOAS is likely to be.

Additionally, don’t just look, listen – a brachycephalic dog whose breathing is laboured, noisy, wheezing or otherwise commonly audible, particularly when just resting, is also likely suffering from BOAS. Not all dogs with BOAS breathe noisily all the time, however.

The flatter and more exaggerated the face, the worse the BOAS will be.

Can mixed breed dogs get BOAS?

BOAS doesn’t occur in dogs with normal-length muzzles, which means that it exclusively affects dogs of brachycephalic breeds and types.

However, a dog need not be a pedigree or even of a specific breed to exhibit BOAS, they only need to be brachycephalic. This means that cross breeds from which both parent dogs, or just one, were brachycephalic may exhibit BOAS too – depending on the flatness of their face.

If a moderate brachycephalic dog is bred to a normal-muzzled dog, the resulting pups will likely be only moderately brachycephalic themselves and so, much less likely to exhibit BOAS.

Can dogs with extreme BOAS be used for breeding?

Currently, there are no laws or restrictions on breeders breeding dogs with BOAS. This includes breeding dogs with very extreme BOAS (and/or BOAS that has been surgically improved, but that ergo will still result in heredity of the condition to the litter).

In fact, some breeders who breed for profit rather than health and welfare deliberately breed extremely brachycephalic dogs with severe BOAS and market them as top quality examples of the breed as opposed to dogs plagued with a lifetime of painful and costly health issues.

Unfortunately there are no regulations or restrictions preventing this from happening.

Should dogs with extreme BOAS be used for breeding? Absolutely not. This is risky for the parent dogs, and results in the inheritance of the condition in their young.

All prospective buyers of brachycephalic puppies should take pains to educate themselves on what it means for a dog to be brachycephalic and what BOAS is and how it occurs. This will help to ensure that you don’t fall foul of profit-hungry breeders producing so-called “designer” dogs or dogs that are wrongly marketed as top quality examples of their breed and with prices to match, which are ultimately suffering as a result of their breeder’s vanity.