There are dormant larvae in the tissues
of most adult dogs and these can be activated around the 42nd day of the
pregnancy and then migrate to the fetuses in the uterus and become active
infections.
Helpful questions and answers..
http://www.vetinfo4dogs.com/dworms.html
This is why a bitch can be "worm free", yet still pass worms onto the pups.
If I knew the pup hasn't been dewormed, I would give a "preventative" dose of pyrantel pamoate, then again in two weeks.
Tape worm segments are easily seen in dog waste, they look like a very short flat worm that has a wave like motion....when they have been expelled for long enough to dry up, they look like a grain of rice, sometimes on bedding, or on the dog's hair around his butt. They also come from a dog swallowing an infected flea. (or eating rodents, rabbits, or other animals that have been infected themselves.) On top of seeing the segments there would be a very long tapeworm hooked onto the intestines, and just the lower pieces shed.
You can also easily see roundworms, but they are not expelled during "every" bowel movement. Neither are tapes for that matter.
Hookworms cannot be seen by just looking.
The pyrantel pamoate will kill round worms and hook worms.
If you have seen the tapeworm segments you need something else such as praziquantel, which only needs one dose, but it would be best to rid of any fleas first.
IMHO, the best way to deal with worms........
Check stools frequently...
And do preventative dewormings, depending on risk and contact.
If your breeder said she didn't give any shots or dewormers, I would believe it. Why would someone lie about not doing preventative care.
Best Wishes,