Large Lump on Leg (might be cancer)

Hey guys. So I am technically a new member but have been following posts on this site for years as I raised my chinchillas and had questions here and there. My first girl that I got, Mochi, just recently developed a large lump on her back leg right around the knee joint. It happened over night. Now, she had hurt herself once before on her front leg, and was so lethargic and refused to come out of the cage for even her favorite treats or dust baths (she is my most active chin and is very good...

Large Lump on Leg (might be cancer)