Reverse sneezing is a fairly common respiratory event seen in dogs (rarely cats) that, while harmless, can be quite frightening for dog owners to witness. Find out what happens during reverse sneezing and what some possible causes are in this FAQ.
Answer: Reverse sneezing or inspiratory paroxysmal respiration, is caused by a spasm of the soft palate and laryngeal area. It is termed "reverse sneeze" because the dog is inhaling air rapidly and forcefully instead of expelling air, as with a normal sneeze.
During a reverse sneeze, which last a few seconds up to a minute or two, the dog is usually very still with the head and neck extended. The inhalation of air can be quite forceful, leading some owners to rush to the emergency clinic. Once the episode is over, the dog resumes normal behavior. Smaller breeds are more prone to reverse sneezing and may have several episodes a day.
Reverse sneezing is caused by irritation to the throat, pharynx or laryngeal area. This can be from excitement, pulling on the leash, inhalant irritants (pollen, strong odors), respiratory infections, post nasal drip, or for some dogs, sudden changes in temperature -- i.e. leaving a warm house to very cold outdoor temperatures.
Rule outs for dogs: grass awn inhalation, collapsing trachea, kennel cough, respiratory infection.
by: vetemedicine.about.com