I'm sorry about your baby

I definitely consider liver shunt life-threatening. If not fixed, it can be fatal. And if not fatal, it can cause aweful symptoms and secondary problems.
This is why I do NOT agree with health guarantees only including "life threatening" hereditary defects. Using the term "life threatening" gives the contract a loophole... I hope your breeder does the right thing.
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~Magnifique Yorkies~
Purchasing from backyard breeders, pet shops, and puppymills perpetuates the suffering of other dogs.
Educate yourself and buy from reputable breeders or rescue.