heart murmur in 8 week old puppy

Question
we bought a shih tzu puppy ( 8 weeks) from a breeder, the dog got ill about 10 hours after coming to our home ( no eating , vomiting , diarrhea) spent the night at the animal hospital on IV , meds etc...tested negative for parvo, on vets advice, returned to breeder, she died 4 days later.  We got another from this breeder, different litter, at vet check up were told she had a 2 heart murmur, we took for a second opinion, this vet sad she had a 4 murmur, both said to return, the dog.  Of course we have fallen in love but do not want to take on a sick animal.  any advice?  she is now 9 weeks old.  we have 2 small kids who have endured one sick dog and don't want to put them through it again, but are torn because we love it, but also cant handle huge medical vet bills....insight????

Answer
Puppies with congenital murmurs can often lead relatively normal lives, though it is difficult to be sure how they will do until one observe how well they eat, grow and respond to exercise.  It seems that there is some disagreement as to the severity in your puppy.  In cases where there is a congenital health problem it is definitely the best financial choice to return, however the emotional attachment is much more difficult to deal with.

I am very sorry for this delayed response.  Due to illness I was away for a time.  If you have current questions please let me know.