Breeder vs Buyer

I would definately let the breeder know, if they alreday know and did not try to work with you, then that says alot about the breeder themselves. If they offer to try and make it right, like offering you options, then they did not intend to sell you a dog that they knew had the problem, then those people are not quality breeders at all in my opinion. If they told you it was a possibility and you took the dog anyway then its your responsibilty.

The female your dog is out of will always have the potential to pass it on and it won't be an isolated situation, so the breeder needs to be notified and they should not breed that female again IMO