Tapeworms look like white rice in the stool and they actually come from fleas. You need to treat your flea problem when you treat the worms. Just give your vet a call and describe the worm to him. He will give you some droncit or some drontal plus. Most OTC wormers will not work for tapeworms.
When you are at the vet's office, be sure to get some frontline for the flea problem as well.
Let me know if you still have questions.