Personally I could not put an animal down unless it could not possibly have a good life. I would move heaven and earth to do whatever it too to make my puppy have a happy life.
I have Rusty that is a Chi/Pom mix that we call our million dollar baby. The breeder would have put him down as he was born with PDA. We spent over 3000.00 8 years ago to have open heart surgery and he is a happy guy going on ten yrs old. We gave up vacations for a year to fix him and I would do it again in a minute.
I cannot imagine not taking responsibility for an health issue any of my puppies have. If one was born deformed I would keep it and love it and take care of it for as long as it lived......UNLESS the vet said it would be more humane to put it down