['Have you ever had a pet that you had to put down? I was so heartbroken when my dog of 16 years had to be put down. this was years ago but it still makes me sad to this day.']
That is heartbreaking, it's always helped me to remember that no matter what happens, you have your memories with them.
I felt sad when my dog passed away. It was a pet that I had since I was 3 years old, and was one of the saddest days of my life.