How are the pups this morning?
Please be sure that your son knows how extremely malnourished these pups are. The chances are good that the pups got roundworms in their mother's milk and maybe from her system before they were even born. The worms have been competing for every bit of nutrition that these pups ever got.
Roundworms encyst in a dog's tissues so completely getting rid of them is going to be a long fight. As soon as pups are over 4 weeks of age and weigh more than 2 pounds, your son can get them on Interceptor(link) [for heartworms] which kills most intestinal worms. Heartworm meds are obtained from a vet or via prescription. I prefer Interceptor over Heartgard because Heartgard contains two pesticides, does not kill whipworms, and I consider the low heartworm med dosage to possibly be too low to be totally effective.
By alternating Interceptor and Safe-Guard (the gentle wormer I mentioned in my first post) every two weeks until the pups are six months would reduce the roundworm load enough that I think Interceptor once a month should be sufficient. You will want to replace a dose of Safe-Guard with a different wormer from the vet if a fecal test finds that the pups also have flea tapeworms. Neither Interceptor or Safe-Guard kills that type of tapeworm.
The pups may also have the parasite Coccidia(link) so they may also need a med for that. "Because these drugs do not kill the organisms, but rather inhibit their reproduction capabilities, elimination of coccidia from the intestine is not rapid. By stopping the ability of the protozoa to reproduce, time is allowed for the puppy's own immunity to develop and remove the organisms."
If these were my pups, I would use Dr. Jean Dodds' vaccination protocol(link) . That means not vaccinating until 9 weeks and vaccinating only for Distemper + Parvovirus, MLV (e.g. Intervet Progard Puppy DPV). See the chart for the rest of the schedule. You may have to call around to see who carries that particular vaccine.
I am not quite as conservative as Dr. Dodds. I would add a single shot for parainfluenza and adrenovirus sometime after the pups are 9 months. I will find the name of one of those vaccines for you.
It is generally recognized now that dogs have been overvaccinated in the past and it is suspected that immune system problems have resulted..
2006 AAHA Canine Vaccination Guidelines For the General Veterinary Practice
http://www.kentuckydachshundrescue.com/vaccinating_your_pet.htm