Omg Ann! I felt panicky just reading your post. I am so glad....your middle of the night vet visit...ended well. Phew....thank God.
Can I throw out another diagnosis? Asthma?
Another thought... my professional opinion of course.
His nose would be draining because he was breathing out of his mouth...when they breath through their nose...the drainage is drawn toward the back of their nasal cavity.
I'm glad Marcel is okay...I'm sure your heart is just now...stopped racing.