I am so sorry to hear this. Am afraid though I won't be of much help.
Yes, you could contact the breeder but don't keep your hopes too high that she will take up responsibilities.
Hopefully when you see the specialist next week they can help you with all your questions. Like someone said before, there are people living with heart conditions and might not even know about it. Now, that you know of her heart murmur you will detect and react much better than if you didn't know. "The devil you know..." Isn't there a saying like that?
She is an adorable little thing. I wish you luck.
__________________ *I hope to be the kind of person my dog thinks I am*  |