I have missed the story on these pups? did you rescue them?
I can relate to what you are going through and your pain
I rescued 3 pyr pups at 10 days old,bottle fed them,watched them open there eyes(literally)watched them take there first steps,we had 2 of them on antibotics and fluid injections for the first few days,it was touch and go,I rubbed there stomaches with warm clothes to get them to potty...all just like momma dog, if not more.The time came that i had to let 2 of them go,it was hard,I cried,changed my mind 2 or three times saying i was just going to keep them but in reality I new that I just did not have the room...I bathed them one last time,groomed them and watched them go to there new homes,I felt like I had lost a couple of my children..I did..the 4 legged kind.Lucikly one went to a family member and the other a friend so I get updates weekly on there weight and vet visits,That helps make it easier.Bear is the one I kept so he is extremely special to me and even more so now with the others gone,I am like a Momma Bear over him.
So I can relate to your pain,Hubby comforted me in saying over and over that I gave them a chance at new life,a life they wouldnt have had,they would have died,I saved them and brought them up to happy,healthy pups..to feel good in that.
I do not know your story on your pups,but I can say.. feel at ease that you have gotten them this far,watched over them so carefully and now time to make a life in there forever homes.The updates will make you feel good abotu what you have done..and then you can say..a job well done.