Blue spot on Guinea pigs side

Question
There is a blue spot that recently appeared on my Guinea Pigs side.  It's abount the size of a nickel.  If touched there she squeals.  Any ideas on what it is.  She eats and runds around as normal.  She shares a cage with another Guinea.  The other one has no spots.

Answer
Hi Becca, wow, I have never heard of such a thing. It could be a growth or a tumor, so she may need to go to the vets asap. Good luck adn let me know if you find anything else out. Sorry I could anot help but I have never heard of such a thing. sorry!