Oh man....I am so sorry to hear this. My friend is a breeder and she had a Biewer kill her pups this summer, but not eat them. I am shocked and so sorry for your loss. I have a litter right now, too, so I can kinda imagine how you feel to lose them. But I'm sure not really. How old are they? I'd be watching real close. I'd probably even separate mom when you are not there to watch closely.
I feel so bad for you.
There is a ton of helpful people and knowledg on this board.
I hope something helps.
Please keep us posted.
Lori