Those are large roundworms in the pics, not a common occurance in eggs but it has happened to a couple of BYC members. Large roundworms can grow up to 6" in length. Then there are the small tiny worms that you cant see that do the most damage internally to a chicken...capillary worms. Of course...
How about 1 day withdrawal period with flubenvet? It wont kill tapeworms though. I doubt your birds have tapes, you'd easily see the segments in the feces.
http://www.twincitypoultrysupplies.com/store/index.php?main_page=product_info&products_id=584
Yes. Valbazen liquid cattle/sheep wormer or safeguard liquid goat wormer can be given orally. Use a syringe without a needle to administer one wormer or the other. Dosage is orally undiluted 1/2cc for standard size birds, 1/4cc for smaller birds. Redose again in 10 days (either wormer.) There's...