The fecal came back negative for eggs. The vet is pretty perplexed, she said she would find out more information for me. She thought it might be something sloughed off from his intestines or it was in the papers he was kept in (which seems unlikely in the extreme to me). She thought if she could find out what was going on that she would have me de-worm the three I have at my house. In any case, I won't find out more until Monday at the earliest.