I completely agree. Our Angus had metastatic bone cancer, one of the bones in his leg was barely connected. Our vet euthanized him, but I sat, holding him and talking to him through the process and for hours after he was gone. I could not let him suffer and almost 4 years, 3 dogs and 40 chickens later, I still mourn him. He was cremated and for now, his ashes are by my bedside table. I couldn't bear the thought of burying his ashes here, because, at the time, it looked like we would be moving to England (hubby was homesick.) Doing what is right, is seldom easy.
I don't think my heart will every actually heal, and I love all of the feathered and furry babies that we now care for and I know that eventually, it will lead to more pain, but that is the price we pay for loving.