well if you got tapeworms, supposedly a good pet med is Valbazen (albendazole) made by pfizer, it says for cattle and sheep...can treat tape or roundworms..I have ordered this because one: it is made in the U.S. and controlled and two: most online pharms sell meds made in India or Asia, and that makes me uncomfortable..
Im in the same bout I showed a doc pics of the worms Ive passed and she said there was no way I could have worms and of course the test came back negative, I just did another stool test from a parasite lab in scotsdale, arizona. Waiting on results..You should give it a try, or maybe try Metametrix lab stool test it actually tests for the DNA of the worms, not just for the eggs. And thats why most likely your test came back negative, they cant test the parts in normal labs, only look for eggs, and if your not passing any, then negative test is the result.