I'm sorry to hear about your kitten. We lost our most beloved Giuseppe to FIP on August 12 of last year, just a few hours before his six month birthday. And now we fear that his companion cat has it now.
You'll know when it's time to say goodbye. We were fortunate to have Giuseppe here at home when he passed. We had scheduled to drop him off at the vet the very next day, but Giuseppe picked the time when my fiance and I were both at home.
His death was the hardest thing I have ever had to face, and now that we may be losing our next cat to FIP I don't know how I'll recover.
Once again my condolences. I know the pain you feel. JUst remeber the good times you had, no matter how short their life is. Giuseppe's life was short, but he taught me so much about love. I learned more about life in his short time on this Earth than I could learn in an eternity. God bless.