I'm really sorry for you lost. Part of us also gone .
Somethings are also difficult to solve, specially at this age. Poison and bacterias they are so many
.
I heard you should avoid to use newspaper sheets to maintain the floor dry and warm for the puppies, cause it has plumb and it is highly harmful for their health, but sincerely at 4 days,I don't think it could be.
My respects,
Marcus
Hello
They were in my house , in a special room, with normaly temperature, dry place, i don't know why, i use newspaper for them when they will be 4-5 weeks old, to make the toilet there cose they are stay in side my house, i never put them out winter cose so cold, and summer cose so warm

they had plaid under them, and i m so sad cose never was in my home that died a liter
Bea