The first time I had to have one of my babies put down, I could not say the words. I just kept saying, "Do what's best for Blacky." Finally, the vet clarified with me that Blacky would not be alive when I went back for him. I have had to say those words several times for my cats and dogs now, and it doesn't get any easier. The only problem with euthanasia versus a heart attack or other sudden death is that they have probably been sick longer.
What really broke my heart was when my Pixie, another black cat, was hit by a car right beside my mailbox. We live on a rather isolated road, which was not busy; yet, no one stopped. She was 16 years old, and so very special. My son was not home, and I could not dig. My neighbor, who had called me when he saw her, offered to bury her. That meant I had to hurry with finding a nice box for her and I had almost no time to say goodbye. The children and I always had a little service for our babies, to thank God for sharing them with us. I did that myself, but I could not take my time because I didn't want to take advantage of good nature. Now my cats are not allowed outside.