Bump behind chinchilla ear?

[XxDailyDreamxX]

Hello!

I noticed this when I purchased my grey chinchilla, but she has a very small bump behind her right ear. It seems to be growing a bit, which is what worries me. I can't see it, but I can feel it. It doesn't seem to cause her any pain. Should I be worried?

P.S. She broke her arm recently in an accident and I was wondering if there's anything I could do to make her more comfortable? She has a week and a half with the cast left.

 

[Zoaea]

When you see the vet to get the cast off have them look at the bump. It could be as simple as a cyst of fluid.