The REVERSE sneeze is like a sneeze that won't "come out", like that feeling when you try to "hold back" a sneeze. Occasionally, excited Cavalier King Charles Spaniels (it can affect any breed of dog, but more commonly short nosed breeds) will suddenly stand still and start making a very loud snorting sound, over and over, as if they are gagging and having difficulty breathing. In cavalier circles, this is known as the “Cavalier Snort” or the “Reverse Sneeze”. A YouTube video of a cavalier making this sound can be seen by clicking here. And here is another YouTube video of a vet explaining the "Reverse Sneeze". In cavaliers, this gagging sound usually is due to the dog having an elongated soft palate. The palate is the roof of the mouth. It is divided into two parts, the front bony hard palate, and the rear fleshy soft palate. The soft palate separates the nasal passage from the oral cavity. (See the soft palate at the top of the drawing below.)
An elongated soft palate is too long for the length of the mouth, so that its tip protrudes into the front of the airway and may get sucked into the laryngeal opening where it may obstruct the normal passage of air into the trachea. This is because the CKCS has a shorter muzzle than the average dog, and therefore all of the dog’s breathing apparatus is compressed into a shorter space than the average dog.
When the elongated soft palate protrudes and partially or totally blocks the airway, the dog no longer can breathe through its nose. Since dogs normally breathe through their noses, they continue to try to do so, thereby causing the gagging or snorting sound.
Block the dog’s nostrils and make it breathe through its mouth.
If the palate is only moderately elongated and does not totally block the airway, most cavaliers are able to pull out of these blockages by themselves. Snorting may be relieved by forcing the cavalier to breathe through its mouth instead of its nose. This may be done by holding the dog's head with one hand and placing the palm of your hand over your Cavaliers nose and inserting a finger or two into the mouth in order to open up an alternative airway while blocking air from entering the nose. You may use two hands if necessary, but if your Cavalier is having a hard time stopping the reverse sneeze on it's own, it's best to help out (please watch the videos above for more techniques and info).
(This article has been excerpted from “Brachycephalic Airway Obstruction Syndrome (BAOS) in the Cavalier King Charles Spaniel” on this website.)