Cancer in a rat?

Our rat Mocha is ill. His scrotum is very swollen. He's been acting lethargic and won't come to me when I call him. Usually Mocha and his brother Max follow me every where and they will come right up to me when I click my tongue. Kristin and I took him to the vet today and we were told that his liver is swollen and it feels like there is some kind of mass in there. His kidneys were okay though. There might be two things going on. One is he has an infection in his testicles and while it's not usual for it to spread to other areas, it can. Two, Mocha could have cancer. Wow! Big word for a little guy. You wouldn't normally think about animals getting cancer, but they can and do. Poor Mocha.

We are hoping that it is just an infection. The vet sent us home with some antibiotics and we check back in 10 days. If it is an infection we should see some sign of Mocha getting better within 3 days to a week. We are praying Mocha will be okay. I'll let you know how he is doing in a few days.