Tumor-like bulge?

[engywook]

This weekend I visited the Tropical Animal House in Helsinki. I had a good time and got to know the owner, but left with a nagging question. One of the adult BPs had some kind of bulge on the underside of its jaw/throat; it looked a bit like it was holding a very small prey item in the process of swallowing. Worried that it might be a tumor of some kind (my first impression), I pointed it out to the owner/keeper. He said it couldn't be a tumor, since it had appeared overnight; he also wasn't worried, since the ratsnake had apparently had something similar before laying. He seems to know what he's doing and to care for the animals, so I'm not terribly worried, but I'm certainly curious (and slightly concerned). I took a picture, hoping to get some feedback here:



Anyone know what that might be? In general, the husbandry was OK -- not as nice as it might be for a single animal, but pretty good for limited staff caring for a large number of animals of different species. A few bits of loose shed and some cases where it seemed like the humidity wasn't right, but basically healthy animals all around.

[SatanicIntention]

Could be fluid buildup from a rodent bite inside the mouth(edema), could be a respiratory infection, could be an abscess. You just can never know without the snake seeing a veterinarian and getting some radiographs or ultrasound done.