I'll post what Jen said incase anyone else was curious.
You want to treat them for Round, Hook and Tapeworms. You could spend a little more from a vet and get one pill that will kill all three in one.
OR you can go to the pet store and look for 2 different things:
1) Tape Worm Tabs, The brand is Tradewinds and it usually comes in a blue and white bottle. But if you find it in another brand or another color, thats fine, just make sure the active ingredient is 23mg PRAZIQUANTEL. It will seem kind of pricey since you only get 3 tablets in a bottle. That should be all you need but remember that if they aren't continually treated for fleas, they are going to keep getting Tapeworms so treat accordingly.
2) You will need some sort of round and hook dewormer. You can look at any pet store near you for it, which will come in liquid or pill form. You can also go to a farm supply store and buy a giant bottle of cattle dewormer which will work fine. Just remember that the active ingredient in this case is PYRANTAL PAMOATE.
*Bottom line is to look for those two active ingredients when searching for dewormers. I am guess the Hartz or 8-n-1 is PIPERAZINE which is in ineffective and often risky ingredient that you want to avoid. The ingredients I mentioned that you WANT to look for are the SAME EXACT thing a vet will give you. I have done research and shopped around on this stuff. Just follow the doses the packages or bottles recommend, treat with the right amount and retreat if necessary.