I feel sorry for any dogs in a breeding program such as that...to let the teeth or any health problem get to a "life & death" state is unconceivable. I can understand and respect a breeder for selling a dog that has a potential health concern/problem that may eventually need to be corrected and is forthcoming with that info from the very beginning. But to let a dog go that long and suffer...that's someone I would not want to buy from.
Everyone may have a bad case out of many but there seems to be just to many from the same circle here.
Praying Mia can recover and live a happy, healthy life with you!