WILL THIS SEASON OF DEATH AND ILLNESS EVER END?

I was cleaning cages today and when I reached in for Paloma I noticed a marble sized lump under her neck on her chest. UGGGG!!!
I had her out playing just two nights ago and I didn't see anything wrong with her OR any of the other girls (and this I would have noticed).
I made an appointment to see my vet tomorrow and see what it is and what can be done. She doesn't look like she is in any pain and doesn't seem to mind when I touch it or even press on it.
She is one of my oldest females and her sister (Nutkittys rat) has just passed...I have her brother and he seems perfectly healthy, but

I guess I will be watching him close now too.
WHAT A HORRIBLE WINTER THIS HAS BEEN!!!
I have now lost 3 rats in the last month or so and now have one with a huge absess or tumor.
