We got my German Shepherd when I began elementary school and we had to put her to sleep the year I was graduating high school.  She was such a great dog to grow up with and we always had so much fun playing.  She was 14 when we had her put down and it was the worst thing ever for my family to do.  Her mind was still with it and she was the same happy dog, but her body just wasn't.  Saffron would fall as she would walk up or down the stairs and she would have such a difficult time to get up.  She was such a fun, playful dog in her youth and it was hard to see her in so much pain and having so much trouble getting around when she was old.  Putting her to sleep was the worst thing my family had to go through so far.  She was a wonderful dog to grow up with and I'm sure she's having a great time, pain free in heaven.