Ok I just bought this pup yesterday and as soon as he poops he poops worms (the little white ones). I was told he was wormed! So my ?'s is....I wormed him myself with some home stuff I bought and then I seen the girl gave me a puppy packet with "Interceptor tab" for worms. Should I wait to give it to him since I wormed him myself??? But he is still pooping worms. He has pooped about 4-5 times and EVERYTIME there has been worms in it!
Not all worms are killed by regular wormers. Tapeworms in particular are resistant to commonly used medicine for worms. Take the dog to the vet and bring a poop sample so the vet can figure out which type of worms the dog has then the proper meds can be prescribed. I wouldn't risk dosing the dog again without a vet's advice. You wouldn't want to overdo it - wormers are basically poisons.
I would definatly go to the vet, before giving anything else. It helps to know what kind of worms you are dealing with. I personally worm my puppies several times before they go to their new homes, and (knock on wood) have not had any go to their new parents with worms.