I have a recused chinchilla whom I believe is anywhere from 10-15 years old. I adopted her and her daughter 5 years ago. (The daughter is also 5) back in June I found a lump on my chinchilla under her arm above one of her nipples, Took her to a vet and they took a poke Biopsy. Over $500 all they said is that’s it’s shows signs of inflamed cells. No bacteria was found. They told me to monitor it as it seems okay. Mid October (over 2 weeks ago) I found it was discharging some liquid. It didn’t have an awful smell but still thought it could be infection. Brought her to a different vet who put her on antibiotics. The antibiotics hasn’t done anything and I brought her back. It occasionally bleeds (but not much) and oozes discharge mostly at night I think due to her moving around. They don’t know what it is and explained worries of putting her under for surgery due to her estimate older age. I am asking if anyone has had a similar situation. She is still eating, drinking, pooping normally and very active.