Sorry to hear that, but I have you beat.
So my wife gets a white mouse (feeder mouse-.99 @ the pet store) from a friend for my daughter. Keep in mind this thing was 1 year old when we got it. That is pretty much the life expectancy of a feeder mouse.
So my daughter falls in love with it. About 2 years go by (this thing outlived it's stay) and I get a call from my 11 year old (at the time) and she says her mouse had a growth on its mouth. Knowing she wants to take it to the vet, and this is the daughter that never asks for anything, I reluctantly say yes.
So, I get a call later that day from my wife. She's at the vet. She says they want $80 to check it out. I reluctantly say OK. The next call I get is that it needs surgery for a tooth that had grown into it's sinus. The bill, $145. I can't believe it, but reluctantly say OK (I love my kids).
So, the mouse comes home and I have to give it medicine. From a needle into it's mouth. Do you have any idea how difficult that is? Just imagine.
One week later, it dies. So it is now burried in a Illusion 88 box under her bedroom window.
Since then (6 months) she has gone though 3 hamsters. She thinks she is the Grim Reaper (poor thing). But has decided to give up the "pet owning" thing.
Now my other daughter has a hampster that she never even takes care of and the thing is living like a champ. Imagine that.
Sorry to take up so much space.