I have one cat that has recurrent bouts with round worms. The shot at the vet works for a while but she manages to reinfect someone for an indoor cat and none of her roommates get them. The vet costs $43 each time I go, office visit, shot, etc. But one dose of the Fish Tapes - 5 capsules - 34 mg. Praziquantel so far has done it and if I do have to repeat, I have 4 more doses!!!