1 - Snoring
This is a Pug fact for the breed in general, so while there will be some Pugs that are perfectly quite while sleeping, most will have some degree of snoring. The reason for snoring has to do with the facial structure of this breed. Great time was taken, over the course of centuries, to develop this dog to have a very flat face and a small flat nose. There are other dogs with this type of facial structure as well, called brachycephalic and this includes: the Bulldog, Japanese Chin, Neapolitan Mastiff, Lhasa Apso, Shih Tzu, Pekingese, Brussels Griffon, Bullmastiff and English Toy Spaniel.
Out of all of these breeds, the Pug has one of the shortest snouts. This creates a very compacted space for breathing passages. In addition, the soft palate (flap of skin above the windpipe) is commonly too long in relation to the windpipe opening and a Pug may have narrowed nostrils (stenotic nares) which can cause snoring as well.
Breathing become even more restricted when the Pug lies down. Some will have a light snore that is barely audible while other Pugs can be quite loud. If this is accompanied with heavy panting and any breathing difficulties while exercising the Pug should be examined by a veterinarian. A small medical procedure can widen the nasal opening and/or shorten the palate to allow for easier breathing