icky....even though he may be clear after the first treatment, you may have to treat every two weeks for a few treatments. Roundworms are common in all puppies.
Take stool samples in every time you go for his puppy boosters. One other thing, don't let the vet give the rabies vax with the other puppy shots. They should be spaced out by 2 weeks. Dr. Jean Dodds' Pet Health Resource Blog | 2013 and 2014 Canine Vaccination Protocol - W. Jean Dodds, DVM