Brachycephalic Syndrome

[littlesquashyguys]

Yesterday, my Pug was diagnosed with Brachycephalic Syndrome. My vet has referred him to a specialist at the Hallam Veterinary Referral Centre, who will be performing the operation (widening his nostrils and shortening his palate) next Tuesday.

My Pug is four and a half, and he has had breathing problems, on an off, for most of his life...but they have gotten much worse in the last 12 months...and, the night before last, I was up all night with him because he wasn't breathing properly. It was very scary and I'm very worried about him.

Last night, I read a bit about Brachycephalic Syndrome on the internet. I looked at some drawings of the inside of a dog's respiratory system (a dog affected with Brachycephalic Syndrome); and it looks like the whole of their nasal/sinus cavity is constricted. If this is the case, how can widening just the nostrils make a difference to their breathing?

Edited August 24, 2011 by littlesquashyguys

[~Anne~]

The nasal cavity is not normally that affected. Your Vet is possibly operating on the nares and resecting them. A canine's nostrils should be round and open, but with brachy breeds and poor breeding, the nares block this opening and it looks more like a slit. Part of the excess skin is cut back to open the nostrils up and allow air to flow easier.

On eof the critical issues with brachy syndrome is that it weakens the parts of the respiratory tract, including the laryngeal walls.

This is a blog piece I wrote on the subject a few years ago;

Pugs are a brachycephalic breed and they share this category with several other breeds of canine including the Pekinese, Boston Terrier, Boxer and the British Bulldog.

The term brachycephalic is greek in origin and comprises the terms "brachy" meaning short, and "cephalic" meaning head.

There are three cephalic indexes. Dolichocephalic (long head), mesocephalic (moderate head), and brachycephalic (short head).

Brachephalic Airway Syndrome (BAS) is a partial upper airway obstruction characterised by more than one condition that affects the respiratory system. Most dogs with BAS will suffer from two or more conditions, hence the latter part of the name 'syndrome' or conditions that 'run together'.

The brachycephalic skull is only achieved through selective breeding. Compressed, narrowed air passages occur in dogs that are selectively bred for a flat face, round head, and short, thick neck and, because of this, the throat and breathing passages in these dogs are frequently undersized or flattened which creates the conditions that make up BAS.

BAS may be caused by any or all of the following:

•stenotic nares (malformed and or pinched nostrils);

•elongated soft palate;

•laryngeal issues (everted laryngeal saccules or laryngeal collpase); and

•tracheal problems (deformed/ narrow trachea).

How do these conditions affect brachycephalic breeds and, specifically, the Pug?

Dogs cool themselves by panting. When a dog pants it provides increased air flow over moist surfaces in the upper respiratory tract through rapid, shallow breathing. The increase in air flow causes an increase in evaporation from the upper respiratory tract. This evaporation process cools the dog.

Even in the most well bred Pug, this process is flawed. To produce airflow through narrowed passages, particularly during warm conditions, the respiratory muscles must generate more force than what is required in most other canines. This effectively places the brachycephalic dog at a disadvantage.

Without unrestricted and easy airflow, the Pug has to work harder to cool themselves in high temperatures. In a Pug with BAS, they have to work twice as hard.

BAS worsens in time. The force of air can result in damage to the soft tissues lining the airways, causing swelling, inflammation, and even inward collapse that further narrows the airways and creates secondary BAS complications. Pugs suffering from any or all of the primary BAS conditions (elongated soft palates, narrow/deformed tracheas and stenotic nares) are at risk of developing secondary complications.

The continued and ongoing stress on the walls of the larynx by forced breathing, due to partial obstruction, creates pressure in effect sucking them inward. This inward pressure causes the laryngeal saccules, which are pockets of thin membranes lining the larynx above the vocal chords, to invert or ‘turn inside out’ which then further aggravates the condition and obstructs the airway.

Continued pressure against the laryngeal walls can also cause them to weaken and collapse. Increased vibrations in the airway result in swelling and irritation of the laryngeal membranes, again further worsening the situation.

Tracheal collapse is another possibility in Pugs that suffer from BAS. The trachea in Pug dogs may be hypoplastic (underdeveloped or narrow) or perfectly formed at birth. In Pugs where the tracheal collapse is caused by pressure of breathing it is called an 'acquired tracheal collapse' to distinguish it from a congenital (present at birth) tracheal condition.

Pugs suffering from any number of BAS problems exhibit noisy breathing (especially during exercise or stress) and heat intolerance. A higher pitched sound and sharper intake of air may be be heard under stress.

Exercise intolerance, cyanosis (blue tongue and gums from lack of oxygen), and occasional collapse can occur, especially following over-activity, excitement, or excessive heat or humidity.

The danger of BAS lies in the very real possibility of death from suffocation or heat stroke.

There are many conditions that can aggravate BAS, including obesity, poor health and poor breeding.

[littlesquashyguys]

(At the beach, replying from my phone)

Hi Anne, thanks very much for this...yes his nostrils are tiny little slits, rather than round holes.