What doesIt mean when a hen open its mouth wide open like it yawning.? Several of my hens do this..ive wormed them a week ago..it continues to repeat it like every 15 seconds or so like its stretches its mouth wide open then shuts it..
The symptoms you describe sound like your hens may have gapeworm. Do they have any other symptoms, like runny noses? Which wormer did you use?
This can be a sign of adjusting the crop, where food and water are stored before moving on to the gizzard for digestion. It is common to see this, but it should not go on and on. Sometimes a crop impaction can occur if they have eaten something large or something like grasses or straw that gets wound up and won't pass. Gapeworm can cause severe gaping, but if they are not having severe distress breathing, and can eat and drink, it is probably not gapeworm. Gapes can only be seen inside the dissected trachea or airway after a chicken is dead. Gapeworm can be treated by giving fenbendazole (SafeGuard liquid goat wormer or equine paste at 1/4 ml per pound of weight for 3-4 days in a row orally. Feel of the chicken's crop in early morning when it should be empty. Here is some info to read about impacted crop: https://www.backyardchickens.com/a/impacted-slow-and-sour-crops-prevention-and-treatments
