This article has very detailed information about the constricted airway and stenotic nares of Frenchies. The following article will give a summary.
Some brachycephalic dogs have stenotic nares.
Frenchies are brachycephalic dogs and one symptom of this type of breed is their stenotic nares. Stenotic nares means constricted or small nostrils. This is a birth defect.
How to tell if your dog has stenotic nares
Stenotic nares in Frenchies can have several consequences. Their breathing may be louder or seem more labored. This might only be noticeable when the Frenchie has been in the heat, or is sleeping, or has been exercising. I have two Frenchies and they both snore pretty loudly when sleeping, but I do not necessarily hear loud breathing normally.
When do stenotic nares require surgery?
If this condition is extreme, or combined with a soft palate, collapsing larynx or trachea, then surgery may be needed. Just having a Frenchie with loud breathing does not mean that stenotic nares is necessary. Some vets who are not very familiar with bulldog breeds may encourage surgery unnecessarily.
What is the surgery like?
If your vet and you decide that surgery is, in fact, the best option, it is generally a minor procedure. Of my two Frenchies, one has had surgery and one has not. Pierre, my Frenchie who has had surgery, was operated on in the same procedure as his neuter surgery as a puppy. The procedure involved widening Pierre’s nostril opening by removing a small piece of the wall of each nostril. His was done with a laser, but this can also be done with a scalpel. There was a little big of scabbing after the surgery, but now you can not even tell he has a nose job!