The best way to prevent respiratory issues is to surgically correct their stenotic nares by removing the excess tissue and creating a nostril to breathe. Studies have shown that if you correct the nostrils in a brachycephalic dog before they develop difficulty breathing (when they are young or at time of spay/neuter), you can actually prevent their soft palates from getting thickened and consequently, prevent them from needing surgery on their palate too. I have seen pugs able to go for a 2-3 mile run because I performed an alar fold resection on them when 7m of age.
We use cautery or surgical laser to perform these procedures. The attached picture shows the right nostril of a French Bulldog prior to surgery and the left nostril already surgically corrected. As you can see, the dog now has an open airway to breathe!! So if you have one of our beloved smooshy faced breeds, we have the ability to greatly improve their quality of life so just ask us if an alar fold resection would help your pet!