That's the overwhelming guilt I am feeling right now, either justified or not.
Don’t fault yourself for loving your friend and having to make the decision for them. I felt the same way, trust me. Our Kitty had cardiomyopathy which alone can cause death and blood clots. She ended up having saddle thrombosis which is very painful and even if you attempt surgery or therapy they have more pain and rarely live through it or much longer. Hard to hear from the vet about your loved one and harder to be the one to decide. They know you loved them!. The Lord gives and the Lord takes away, blessed be His name.