Just a few links that may help. If you google: collapsing trachea vs reverse sneeze there are a lot of helpful links plus you tube videos.
Reverse sneeze seems to come on quickly and they breathe in and out rapidl. I massage their necks or put my fingers over the nasal passages and it usually stops quickly. My Baxter does it usually when he is excited about something.
There are SO many degrees of collapsing trachea. One thing I want to let you know is that a chest xray can be done to diagnose BUT if the trachea looks ok, that does not rule out CT. If it does show up then yes, they have it. The most accurate test to diagnose CT is a flouroscopy.
Please don't fear him suddenly dying from this.....the ones who die have symptoms prior. It isn't like a sudden cardiac arrest. Of course, don't let that knowledge keep you from taking your boy everywhere (I doubt you will stop as it sounds like you love spending time with him!), but don't be fearful! I have had pups with CT live long lives and die from other causes. There are SO many degrees of CT AND there are treatments.
Maybe these links might be helpful to you:
https://chihuahuaguide.com/chihuahua...apsed-trachea/ https://www.yorkietalk.com/forums/di...d-trachea.html https://www.yorkietalk.com/forums/si...s-trachea.html