Your question about flea treatments brings up a very good point. The minimum age and weight brackets are meant as a guideline only. If your puppy is slightly outside of the recommended age or weight does not mean that the product w8ll be harmful but only that you may need to make an adjustment in how the product is administered. Your vet can guide you in selection and dosage. For the tapeworms, be sure you mention that you saw tapeworms in the stool to your vet. The standard "worm check" does not routinely pick up tapeworms and typical "dewormers" are not effective against tapeworms. The best approach is if you see tapeworm segments in the stool treat with either Cestex or Droncit.