I am so sorry for your loss. Please don't blame yourself for this, you did all you could, and remember the dog doesn't know any difference. He didn't know you even had the option, and I'm sure he had an amazing life with you. Your wife should have supported you more, and even if you weren't in the picture, I am not sure how she could put material objects before another creature's life. If she was willing to do that, it sounds like maybe she may not be the best wife to you either. Even if she doesn't respect other animals, she should have at least respected the fact that he meant a lot to you and supported it. I'm sorry, you deserve better. You sound like a great guy and you deserve a woman who loves animals and would do whatever she could to save the dog for you. I hope you don't blame yourself, I hope you heal and feel better. I also hope you and your wife can get on the same page, perhaps you could talk to her and explain how you feel and help her to feel more close with dogs and develop more respect for them? Also maybe explain that you'd like her to be less materialistic and to support you more than she does. I truly hope everything works out for you. If I had a husband and he did that I would not know what to do. Sending positive thoughts.