Hen sneezing and wheezing

Hopefully they just inhaled too much of the poultry dust. If it was DE or had DE in it, you should know that DE is very irritating to the respirator tract. It might be they would clear up with fresh air and getting rid of the dust in their area.

 

Are there any other symptoms, like coughing, swelling of the face, discharge from the nostrils, or heavy breathing? I doubt that the dusting two weeks ago has anything to do with your birds symptoms. I think that it could be a respiratory disease.

Chronic Respiratory Disease is one possiblity. It moves slowly through a flock, sometimes causing almost no symptoms, other times causing many birds to be affected. Just in case this is the disease, I'd get Oxytetracycline (sold under names such as LA200, Tetroxy HCA-280, Duramycin, and Terramycin). Tylan50 or Tylan200 are other, stronger, antibiotics that can treat respiratory diseases.

It is also possible that it is a virus-caused respiratory problem. If so, antibiotics won't cure the disease; they will only prevent secondary infections. All you can do is keep the chickens warm, well fed, and hydrated.

Good luck, and hope this helps! Keep us updated!