Treating Pulmonic Stenosis is going to be costly. Consider if you really want to keep this puppy. Your breeder should have a return policy where they will take the puppy back and care for it themselves within a reasonable amount of time (usually a year or so) if a chronic condition arises. Then they should replace your puppy with another puppy of equal value. Your breeder may offer a refund in exchange for the returned puppy, but many breeders do not do refunds.
It is a difficult decision to consider. Just know that any chronic condition is emotionally and financially taxing. If the breeder is in a position to take back and properly care for the sick puppy and replace it with a healthy one, that is often the best route to take. I guarantee you that the next puppy will love you just as much as this one.
Each situation is different though. My puppy has an underbite, is blind in her right eye, and has dry eye in her right eye. She also had to go to the emergency room for coccidia within the first two weeks of owning her. I almost gave her back to the breeder. But, it is my opinion that my puppy will receive better care and more love and attention with me. I got my Mishka from a Backyard Breeder, and I wouldn't want to return her to that environment.
Whatever you choose, I hope everything works itself out for you and your puppy.
