Bloodwork came back today. Everything looked fairly normal (some values were a bit too high/bit too low, but nothing that really indicated anything) except for the fact that she is severely anemic. (And if Jess reads this - I did give her some prednisone encase there is some kind of autoimmune hemolytic anemia going on...figured it wouldn't hurt, correct?)
So while cancer is still a possibility, we really won't know for sure until we look at the spleen. My vet is going to call a specialist she knows and make sure she is on the right track and to discuss the surgery with him, then we're going to go from there.
Right now, the most likely course of action will be a splenectomy. But, because she's so anemic, surgery is very, very risky and will likely kill her unless she has a transfusion. Unfortunately, transfusions for ferrets aren't a dime a dozen. Fortunately, one of my old lab partners has ferrets and she said she would be willing to have her male donate blood for Rinnie's surgery if he is fit for it.
So we'll see. Right now my main worry is cost - I get half off all procedures at work, but I still really can't afford much. I'm hoping for a total cost no more than $300 (which would mean it was a $600 procedure), because much more than that and I'm not sure I'll be able to do it.
Rinnie is doing fine. Still eating, drinking, and going to the bathroom like a good girl. I kept her in at work overnight last night as I wasn't coming straight home after my shift and the vet staff doted on her the entire time. She has them all smitten, even the ones that were originally leery of ferrets. She's back home now; I can tell she and Dameon missed each other because they immediately started grooming one another and now they're cuddled up sleeping together. I had to remodel their cage for her, though, since she can't get around very well. Easy access drinking and food, plus a different litter box that she doesn't have to climb up and over to get in to (which I think Dameon will appreciate, too, as he's been having problems with that lately).