LB - if you're treating with ivomectin then you shouldn't need an additional wormer (panacur etc) as the ivomectin, like the noromectin, treats internal & external parasites. Mange in a piglet, for example, can be a real problem if left untreated and can, in very extreme cases lead to death.
http://jas.fass.org/cgi/reprint/68/6/1495.pdfFrom what I can see Panacur only treats internal parasites - the only oral treatment I can see that does both is a noromectin pre-mix
http://www.vetmedsdirect.co.uk/products/Noromectin-Premix-Pig-5kg.html it's really expensive

I hope this next comment doesn't upset anyone (and I apologise if it does, but feel I have to say it

) If you aren't prepared to inject your pig (or pay the vet to do it) then you shouldn't be keeping pigs - how are you going to keep them fit and healthy otherwise ? Please don't get me wrong - I don't
like having to do it (and Bruce always does the boars

) but it's important for their health and welfare that they are treated EFFECTIVELY for internal
& external parasites. It's not such a concern for folks who are just raising a few weaners for slaughter (providing, of course they've been wormed prior to you getting them) but anyone who's breeding should be keeping a medicines record and be sure they are treating on time and for the appropriate conditions.
Karen x