
The norm is to worm puppies from 2 weeks, and then every 2 weeks to the time they go home, using a gentle worming syrup. And mum needs to be wormed at the first puppy dosing, using a normal adult wormer as she will be infested by any the puppies passed in their stools while cleaning up after them. I have always done this, plus worming my bitch before being mated, and recommended the new owners, who go armed with a complete worming history to show their vets, to get their puppy wormed again at around 3 months. They might of course, have a fecal done first, so they know what needs treating.
I only once saw worms from a puppy - it was our first litter (and I didn't pre-worm mum!). He was the only one of two only in the 'litter' to survive, and me thinks probably copped all the worms that were around. I couldn't look at spaghetti for years after seeing what came out of him, poor wee mite. I never saw worms again in our litters, but the buy in we now have, who came to us at 4 months, said to have been wormed, started producing live roundworms and as his stools were far from right, I had a fecal done which showed up roundworm ova, and GIARDIA. And he came from somebody in the breed I'd known since I started! Reputable breeders eh.
Note, the 'gentle worming syrup' usually only works for roundworms, but I'd not expect any of mine to be harbouring anything other than roundworms as babies.
"I told her to re worm mum or they will pass back and forth" Unless mum has a bowel movement in the whelping box, worms shouldn't 'pass back and forth', just from puppies to mum.