My bad day was yesterday. My old english pointer came up to the house and had been shot. I had to put him down. 
I am so sorry for your loss S Clark.
I had to euthanize my black labrador retriever Apollo in 2002, he was almost 13 and had a tumour rupture in his chest. I was sitting in the vets office when he walked into the room with the x-rays and said that it was very, very bad. I can tell you that I died a little bit inside that day. Apollo in his old age did not like the vets office and I asked my vet if he could come over and euthanize him at home.
A word that I very seldom use is "hate." I can tell you that I hated signing the paperwork required for the veterinarian to euthanize my wife's and I best friend.
We had a very quiet afternoon with Apollo at home, I was lying beside him gently patting and telling him how he was such a good boy - he was a kind soul. The vet arrived and asked if we were ready. I remember telling Apollo "I love you" as the vet gave him the injection and I watched the life drain from his eyes - our best friend passed quietly away. It was one of the hardest things I have ever had to do in my life, but Apollo needed me to be there for him.
I believe that when anyone experiences a loss, you never really get over it, but learn to live with it and perhaps we become a little "numb" inside. I still shed a tear for Apollo from time to time and he has being gone for almost 10 years now.
Apollo
