My Blackie died of renal failure. Believe me, you'll know. His first symptom was convulsions. The vet "flushed" his system several times that year when it looked like the end. However, one morning he felt hot, lay beside me on the bed and didn't want to do anything. I took him to the vet. The vet told me he was not in pain, but feeling completely miserable. When there is no more quality of life, and the vet cannot flush the system successfully of the poisons, he will advise you that the time has come. Often, this shortens your baby's life by a few days, but it also ends the misery they are suffering. I wish I could tell you it's easy, but it's not; it hurts terribly. You just have to know that you are giving her your last loving gift, relief. If you can ease her suffering, and the vet says there's no hope, please don't hesitate. You can stay with her to the end.
I have never forgotten my Blackie. I loved him so much, and still cry when I think of him. But he gave us 16 years of joy, and I thank God for sharing His little creature with us, for trusting that we would take the best care of him that we could. This will be very hard, and my heart aches for you. Shed the tears, and share your pain with us, if it helps. We understand. God bless you.