Just keep an eye on the litter very closely as hypoglycemia can be dangerous.
There are so many reasons but for now you should keep a closed eye on them and if your "guts" tell you just make a vet visit.
It is very hard to give advice like this without seen the puppy and if there is nothing you will go crazy thinking of so many possibilities .
XOXO
__________________ "The reason a dog has many friends is because it wags it's tail instead of it's tong " [I]Smartpuppiepets@yahoo.com /I][ |