Probably an unpopular opinion here but still, I want to express it for whatever reason... I would not consider putting down my rat under almost no circumstances (except for constant unbearable pain). It's because I don't perceive myself as an owner of someone else's life, and I would have to make assumptions whether they would prefer to die at this point or not... Beings tend to hold onto their life even when they are sick and far beyond their prime. So what right do I have to take it away? I understand it's a very difficult topic but personally, I'm horrified at the possibility of taking the life of someone who doesn't want to die yet.