Brachycephaly and Brachycephalic Airway Syndrome (BAS)
While there is certainly a lot that could be said about the practice of breeding purebred dogs, a lot of attention has focused on extreme brachycephalic faces, and the Brachycephalic Airway Syndrome (BAS) this causes, and rightly so. Many inherited problems in purebred animals have been selected accidentally, but the extremely shortened faces of brachycephalic dogs have been selected deliberately to appear to human aesthetics, to the marked detriment of these dogs.
What is brachycephaly and Brachycephalic Airway Syndrome (BAS?)
Brachycephaly is a term used to describe skulls as being broader and shorter than typical for their species. You can use the cephalic index to compare skulls between members of the same species, or between closely related species (don’t bother trying to use this as an indicator of race). There is obviously a spectrum between skulls that are longer than average, about average, and shorter than average, but it is those that are much shorter than average which we are concerned with in this article, because they are suffering with brachycephalic Airway Syndrome.
Not all brachycephalic dogs have BAS, but the shorter their muzzle, the more at risk they are.
Brachycephalic Airway Syndrome is a collection of conditions where there is excess soft tissue within the shortened airways, making it difficult for the dog to breathe for its entire life. This causes significant suffering, imaging trying to go about your day but you can only breathe through a plastic straw.
Is X breed Brachycephalic
But is it bad?
The more extreme the brachycephally, the more likely the individual is to have Brachycephalic Airway Syndrome and suffer because of it.
A mastiff or a rottweiler might be brachycephalic, but (hopefully) not to the same degree as a pug or french bulldog.
What happens with BAS?
Imagine you’ve taken a perfectly normal dog head, and shortened the bones of the face while keeping the same amount of soft tissue, forcing it to be packed into a smaller space, because that’s what we’ve done with these brachycephalic dogs. And the more soft tissue we pack into the reduced space inside the skull, the less space there is for air, which is rather important for the whole ‘breathing thing’.
Stenotic nares: On the outside, you can see nostrils that are pinched shut, already restricting the flow of are before it even enters the dog. Surgery can be done to open these nostrils.
Long soft palate: Because everything in the mouth is crowded, these dogs often have a long soft palate, a flap of flesh that prevents food entering the airway. If it is too long in the dog, it will flap and close off the airway even when they’re not eating, and can swell to become even more obstructive over time. Surgery can be done to resect the long soft palate also.
Hypoplastic trachea: If the trachea (windpipe) is undersized relative to the rest of the dog, there is no surgical remedy for this. Affected dogs are also often prone to collapsing trachea, where the cartilage of the trachea collapses when the dog breathes heavily, and frankly most dogs with BAS will breath heavily a lot of the time.
Everted laryngeal saccules: A normal laryngeal saccule is a bulging of flesh either side of the larynx, but in dogs with BAS who are breathing hard for much of their life, they can be sucked inside out (everted) which occupies even more space in the already restricted and crowded airway and makes the dog struggle further to breathe.
Hypertrophic Nasal Turbinates: That shortening of the skull I mentioned earlier? Does not apply to the complex lacework of bone that usually occupies the nasal sinuses, moistening inhaled air and allowing for a sense of smell. Some of these dogs have their nasal turbinates pushed backwards into their airway, or grossly thickened from constant suction of the airways.
Gastric reflux/vomiting: The constant struggling to breathe results in increases negative pressure within the thorax, which makes these dogs prone to gastric reflux and vomiting. Some of them also have hiatal hernias (stomach herniating into the thorax) to make it even worse. And if they inhale they inhale that vomit, they’re not built well enough to cope with that aspiration pneumonia very well.
And these are not the only structural issues bred into these dogs by selective breeding, only the ones associated with the flattened faces.
So what’s the solution?
Longer faces, obviously, and we need breeders and breed clubs to get on board with this, and start prioritizing the health and welfare of these dogs. We love them, right? They deserve to breathe by default, not just after thousands of dollars worth of surgery.
But 'longer’ is subjective. Perhaps we should be pushing to demand a minimum muzzle length, or a maximum skull width to length ratio? Or alternatively, disqualify dogs that have muzzles too short for their teeth. If we define 'too short’ as 'not enough room in your skull for all your teeth sit straight’ then there should still be plenty of room for the airway
Look at this very familiar example of a normal muzzle and a brachycephalic muzzle, and note the severe distortion of the dental alignment, particularly of the premolars and carnassial teeth in green and blue. If rotated teeth disqualified dogs in the show ring, and therefor from breeding, that should prevent the extreme brachycephalic features that are becoming more popular, and their associated suffering.