You can see from all these posts that you are most definitley not alone in your feelings. Those of us who have loved and lost a dog all feel this way. No matter how sick, how hopeless the case, we still feel guilty because at the end of the day we are the ones who made the decision to end their suffering. It must comfort you to know this and to know that many others (me also) will feel this way again in the future. I lost Tara just over eight years ago now and I think about her every single day, sometimes with a smile, sometimes with tears. That's because we love them, and at the end of the day that's all that matters, how much we love them.