Any suggestions?

[DragonLord2330]

One of our boas head is swollen and he seems somewhat lethargic, the swelling is basically at the tip of the snout. It is not from trying to get out of his enclosure, as the problem just occured "overnite". He also seems to be "yawning" more lately. Husbandry is correct, he is eating fine and just shed last week. He is about 3.5 to 4 years old. I just mated him with one of our females the past week. Any ideas?
thanks,
john & wendy