Growth on side of face?

Question
My dumbo rat (male, age unknown) developed a growth on the side of his cheek a couple of weeks ago. It has grown, and I haven't had the money to take him to the vet recently. He's become very sluggish and won't eat as much. I've been giving him a tiny bit of antibiotics (amoxicillin) mixed in with some apple sauce/Nutella to help it, in case it's an infection.

What is it on his face?

Answer
Please go to my website at sandyscrittercity.com and refer to the page TUMOR ON SIDE OF FACE.

Let me know right away if this is what your rat has.  It is vital you go there and compare because if it is, it is cancer and nothing can be done but keeping him comfortable.

It may also be related to his teeth, but if its a mass that keeps opening and not healing (like an abscess that wont heal) this may very well be zymbals gland tumor.

There are several photos to use for comparison.