It’s troubling to see so many vets doing rhinoplasty surgery on 3 to 4 month old Shih Tzu pups. Puppies teeth during this time and a lot of times their nostrils and gums swell, making them sound like they can’t breathe. Why risk putting a young pup under when more often than not, swelling will go away and their breathing will return normal? I think many forget this is a brachial breed. If your pup is 5 or 6 months and having difficulty sleeping, playing, and constantly trying catch their breath, etc, then maybe yes, you and your vet may conclude surgery may be necessary to help with breathing.
Little Remedies saline spray will help alleviate some of their stuffiness when they are teething.