Hi, I'm so sorry you are facing this heartbreaking decision, and it can be a struggle to know when the right time is to say goodbye, it's one of the hardest choices you'll ever face for your pet. Unfortunately we raise our pets like our children but their time with us is never long enough. There is no right or wrong answer, but you will know in your heart, and you know your dog. When he stops enjoying life, or he is in pain, or everyday things like walking, playing, or climbing stairs become a struggle, then you will know it's time. No one would ever think bad of you for helping your baby cross over the rainbow bridge, you love your baby, and you don't want to see him suffer. Spend time with him, let each family member have their individual time with him, and have a special day with him, doing things or going places he likes, and take some family photos of him to have that memory.