So I have, or should say had, twenty 7 month old hens. Recently, I noticed they weren't acting right. It's been almost a week since I've noticed this, and I've lost almost half of the hens, and what I thought was roundworms doesn't seem right. They have had every symptom of roundworms: Weight loss, shallow breathing, lethargy, and finally, being unable to even stand. I've treated them with Ivermax, Apple Cider Vinegar, and Oregano Oil, but they keep on dying, leaving me more confused with each death. So my question is: What do they have, and how can I stop it?