I cried when I read your post. Your story is very sad. I am so so sorry for what you have gone through. Bailey was a lucky boy to have parents who love him so much.
I understand the sense of guilt you are feeling about not trying the lasix, but really as parents we DO know when our babies best interests are not to be helped to stay here, but rather to be helped to go...to the Rainbow Bridge. There comes a time in their treatment when we just know any further attempts at keeping them alive are in all honesty, futile. They serve only to keep them here for our sake, and because we love them more than we love ourselves, we make the heartbreaking 'decision'. It is a selfless gift of love, although a harrowing, mortifying, deed.
Bailey had a wonderful life with you, and he sounds like he was a fun-loving, active boy.
I too know how heartbreaking it is when they are unwell in their body, but mentally, they still think they are a puppy, and they want to run and play and chase....but they just cannot. It absolutely levelled me when I saw my beautiful Jetson go through that. It broke my heart.
All I can say to you Gen, is that it really does help to be here at Pet Loss. There are many many of us who truly understand. We understand your love. We understand your loss. So come here often and read, and talk, and tell us all about your beautiful baby. Do you have any pictures? We'd love to know him.
Sending you many comforting hugs,