Sally, 10 month old BR pullet, is starting to gasp again. She presented with this problem last week. I separated her from the flock and keep her warm and well fed. She seemed to recover but is once again throwing her head forward and opening her beak when she breathes. There is no discharge from her nostrils or mouth. No change in her eyes, weight or appearance. Her appetite is good and poo looks fine. The flock gets organic layer feed free choice, and treats every day of greens, yogurt, cheese etc. Sally is the only girl with this problem. I'm starting to think she has gapeworm. I can't see anything in her mouth or throat - looks the same as the other girls to me. I know levamisole or thiabendazole is used to treat. If I can find the meds, what is the route of administration, dosage and withdrawal period? Should I treat everyone? Sounds like gapeworm can be passed directly. How can I be sure she has gapeworm? Help, please, if anyone has had any experience with this.