Some breeds of dogs snuffle and snort much more than other breeds due to restrictions caused by having a shorter muzzle area. The faces of dogs in these breeds is so short that the soft palate enters part of the throat and causes the dog to make these noises. Dogs with short faces are known as brachycephalic breeds and the condition that causes them to snuffle and snort is called Brachycephalic Airway Obstruction (BAOS).
The snuffle and snort sound is known as paroxysmal respiration. "Reverse sneezing," is a way of describing the sound. However, the sound made by brachycephalic dog breeds is not really a reverse sneeze. It may be louder or more frequent when the dog is excited, as less air gets to the windpipe, or trachea.
Some bracycephalic breeds that snuffle and snort due to BAOS include the pug, bulldog and Boston terrier. Pugs are originally from China and are light brown in color with a darker face and eyes that protrude. French bulldogs have a darker face like the pug, but may have a white area on the chest. Except for the BAOS-related snuffling and snorting, French bulldogs are thought to be fairly quiet small dogs. Unlike French bulldogs, Boston terriers are said to be fairly noisy and bark quite a bit. In addition to the snorting noises, Boston terriers tend to drool as their jaw skin hangs down.
Bulldogs can have serious breathing problems caused by BAOS, while most of the other brachycephalic breeds, including the Pekingese, Boxer and Shitzu, are not as likely to have serious respiratory issues. Hot temperatures can cause all brachycephalic breeds to not only snuffle and snort more, but to have problems staying cool enough. These breeds cannot cool down as easily as other dogs as they cannot usually circulate enough air fast enough to be able to pant easily and effectively.
Sometimes, surgery may be required to help dogs breathe more easily. Brachycephalic dogs that snuffle and snort usually have a narrowed trachea, or windpipe, and/or narrowed nostrils. Not all bracycephalic dogs will have the same degree of BAOS.