Noticed this little lump on my cavy this morning when playing with him, It's surrounded by hair loss and brown specs. I'm trying not to be a concerned parent but it's hard cause I don't know much about guinea pig skin conditions. Any help in guiding me towards proper treatment or anything is greatly appreciated. There are a couple pictures attached. The pig is almost 5 months old, healthy otherwise, male, well fed, happy, and handsome as can be.