lip growth?

Hello, this is my first time to this site and it seemed very informative from what I've read so I thought I would give it a shot.
When I came home from work today my dog seems to have a swollen or infected lip. From a little googleing it seems like Lip Fold Pyoderma but his mouth doesn't smell horrible.
Below is a picture of what it looks like. Please, any help would be very much appreciated!
http://i41.photobucket.com/albums/e2...nana23/002.jpg

It could be a number of things. A bee sting if you have a dog who likes to chase bees, an accidental bite to his own lip, an infection caused by bacteria that grow in a food bowl that isn't washed often. If the area looks clean and isn't getting huge and it isn't bothering the dog I would wait it out a few days unless there are any changes for the worst.

Is it warm at all? Does it seem to bother him? Is he eating/drinking normally?