https://www.backyardchickens.com/forum/viewtopic.php?id=88445 This is the original thread that I posted yesterday about my listless, not eating, yellow pooping, head shaking 6 month old laying ullet. After looking into wormers on the advice given in this thread, and reading about the different worms, I came across gapeworms and it makes total sense. They come from earthworms and are common in chickens who live in dirt (like mine), they cause respiratory symptoms since the worms lodge in the chicken's throat. They also cause the chicken to shake their head a lot in order to try and dislodge the worms. Has anyone every encountered this? Did the chicken survive after being treated?