Collapsing Trach or Reversed Sneezing

Question
How can you tell the difference between a collapsing trachea and a reversed sneeze?  I have a little Maltese/Pom and no one can seem to figure out which it is that is going on when he has his episodes. The vet is not even sure. He makes this gagging, honking like he can't breath noise and his sides suck very far in like he can't get any air.  I calm him down by rubbing on his sides and talking gently to him and they usually subside quickly.  They are usually brought on by excitement but he has been awakened with such episodes when he was perfectly relaxed. Help!!  They are very scary.

Answer
The honking is the key here. They don't honk with the reversed sneezing but they sure do honk with a collapsing trachea.
They have a harder time getting in air also which is why he is sucking in his chest like that. When his trachea collapses there is maybe one centimeter of space for air to get past into his lungs. It much more scary for him than it is for you.
This falls under the category of COPD, or chronic obstructive pulmonary disease.
Unfortunately there is no effective treatment for it at this time.