Thanks both of you for the response! Good question on the drinking thing. One time he got wheezy and bubbly the night after drinking a lot of water. But today and yesterday I have no explanation. He hasn't had water in a while.

The bubbling is very slight sometimes. There is no moisture visable on the outside of the nostril, but if you look closely, you can see a small bubble inside.

One more interesting sidenote. It seems like it is only in the left nostril ???