What exactly are the signs of gapeworm?? I had one hen die recently, she stood around acting like she was gasping for air. I have another starting to act the same way. I swabbed her throat, but it was clean. I put some ivermectin on the back of all the bird's necks. If it is gapeworm will the ivermectin get rid of them?? The are not snotting or congested or anything like that.