Where do you draw the line? My concern is that ai’ve been following the litter’s progress and this one has always been big. Also, I’m guessing because of the size, the puppy is a little off balance and kind of plops down frequently. I thought I’d see that improve but it hasn’t.
...Unless that puppy is 3 or 4 months old, plopping down suddenly and frequently's pretty normal. it's not weight related - unless these dogs have ROLLS of fat - it's lack of coordination. Same as the number of times and frequency of a newly walking human baby plopping down on their butts.
Most baby puppies are kind of pudgy. They don't walk very well yet, either. If they have a distended tummy it might mean worms or other parasites, but you can tell "distended" from "just pudgy". Where are you looking at puppies?