Originally Posted by
Altenweg
My first instinct is to be really mad that you bred your dog even though you obviously have no idea what you're doing, but it's too late for that.
What did the vet say when you took them in for their first exam? Is this something that's just recently started occurring or has the puppy been lethargic from birth? Has the vet done any tests on the puppy to determine if he has any health problems or birth defects?
If you haven't taken him to the vet then I suggest doing so. It could be that he just doesn't have as much energy as the rest, or it could be something serious. A vet appointment is definitely called for.
On a side note, please don't breed your dog, have her spayed, there are enough unwanted dogs in the world already. Leave the breeding to experienced licensed breeders.
Good luck.