Reverse sneezing (Pharyngeal Gag Reflex) is a sudden, rapid and extreme forceful inhalation of air through the nose causing the dog to make repeated snorting noises, which may sound like he is choking.
It sounds like the dog is trying to inhale a sneeze, and it is therefore known as reverse sneezing.
Reverse sneezing is often caused by irritation of the palate/laryngeal area. It causes a spasm in the muscles of the pharynx. Reverse sneezing is characterized by honking, hacking or snorting sounds (gasping inwards). It primarily occurs when the dog is excited, but it can also happen after drinking, eating, running, or pulling on the leash.
A typical episode lasts only a few seconds, but some dogs may experience this for a few minutes and usually several times a day. Most of the time you can stop the spasm by gently massaging the throat of your dog, or briefly closing its nostrils until the dog swallows.
In some cases reverse sneezing is caused by foreign bodies in the nasal passage (grass blades), irritation from allergies or irritants (pollens, smoke, perfumes), or even tooth root infections. In those cases you should always consult a vet.
If the dog is having repeated attacks of reverse sneezing, your vet may prescribe antihistamines to see if that helps stop the sneezing.
When reverse sneezing occurs right after the nose-inoculation against kennel-cough, it would be advisable to give the dog some antibiotics.
Most dogs that have infrequent episodes of reverse sneezing, can lead a perfectly normal life, cause reverse sneezing is a harmless condition and medical treatment is not necessary.
Although, it is important not to confuse reverse sneezing with a collapsing trachea or a heart problem. In case of doubt, it is important to have the dog examined by your veterinarian.