sick, big lump

Question
My guinea pig, Trig, has a lump about the diameter of a penny near her rump. It has significant hair loss, and the skin tone is speckled. I'm scared for her because I don't know if she'll be okay or not. Is it cancer? What can I do? My parents say that because she's a rodent, they won't take her to the vet.

Answer
I wish I could tell you without the benefit of seeing this spot that it is or isn't cancer. But you have to understand that trying to diagnose something on a description is nearly impossible.

If you could take a picture to send and attach to your message it would make it much more likely that I could help to identify it. But without a picture it just can't happen.  I can tell you that guinea pigs are not prone to skin cancers.  That's not to say they will never get them, it's just that they rarely do.

So please Alex, send me a picture. Otherwise you're asking me to give you an answer to a nearly impossible question.