I am not such an expert as Matt, but in case you are also dealing with round/thread worms fenben low dose will be a benefit in any case. The double dosing 10 days p month is a knock out, but this configuration is mainly for threadworms really. If you are primarily heavily infected with flukes then maybe try with the low dosing first. I would say see how it goes. I know some others treated certain flukes with fenben, and i guess the best way to know what type you got is to try! Should you see you have a response to fenben you may even try the 10 days regime. Time it around the full moon, it helps a lot.