2 year old hen started "gurggling, sneezing, coughing" last week. She also sounded "hoarse". Egg laying had stopped 2 weeks prior. Otherwise no physical symptoms, looked fine. After two days two other 2 year olds were also sneezing coughing and doing strange movements with heads and a 6 week old chick was doing the same. I guessed at gapeworm as all my girls free range. Six days ago I dosed all the adults with Safeguard liquid 3ccs right down the throat, and mixed the same in the 6 week old's water. Everyone seems to improve greatly. The original hen is now very liquid sounding again - could this be a relapse of gapeworm, does this happen??? I couldn't find any reference in the posts to it being a thing that comes back so quickly - should I have givin more safeguard???? Any help would be great - hate for them all to start again!!!