panacur is basically worthless at least at out place... Several years ago, I was losing a few lambs, and the whole bunch just looked wormy.. but b/c i was deworming them with panacur, I thought it much be coccidios, or something else... Stool sample yielded just regular ole worms, I think stomach, or tape, or whatever, anyways, that's not relevant... Vet told me to give some ridiculously high dose of Panacur for 3 days in a row.. Something like 12 or 15 cc's per lamb... He said deworm them, and 10 hrs later bring in stool sample on a lamb. We'll check it out.. He said after the first hr, 90% of the worms that will get killed will be dead, but to go ahead and give it 9 more hours...
Tested the first lamb on day 1- no change in stool sample
tested a different lamb on day 2- no change in stool sample
tested lamb 1 and lamb 2 again on day 3, both had changed just enough to notice a change... But still dangerously high worm loads...
dewormed the lambs with valbazen- tested stool sample a couple hours later-- almost no worms... same 2 lambs.
If my memory serves me correctly, I think we lost 4 or 5 lambs from using Panacur... that many in a group of 20 is not good odds....
I read the label on Valbazen and it says that... as a result, I used it in last 1/2 of preg... never had a problem. It wouldn't say it's safe on the label, if it weren't...
I had a friend once that had a ewe with tapes, and he couldn't get rid of them- tried for 2 years to get rid of them... Gave her HUGE doses of everything under the sun... still had them... Finally he got sick and tired, had an old jug of arsenic in the corner... gave her a slight dose of that- figured she'd either live or die!!!! she lived, and the worms died... I don't recommend this though!!