I take him back tomorrow (it's almost a 2 hour drive!) for a rhinoscopy. If a foreign object is seen, it'll be removed. If there is any sign of tumor :( a biopsy will be performed, and he will have to stay the night because there will be much bleeding. Which means I'll have to drive home alone, and return on Friday to pick him up.
Please, BT Buddies, send good karma our way.