I have got 600 broiler chickens at the mo, with 100 being slaughtered every week. My birds are all in the same structure but age separated by half wall dividers, gates etc. I have never had a problem with disease before UNTIL..... My chickens were flooded about 2 weeks ago. Torrential rain poured through my houses and I lost ALOT, esp the babies. Almost instantly my chickens began coughing, sneezing, wheezing and gasping and I'm losing 3 a day. Some are severly growth retarded and others look permanently fluffed and miserable. Am I correct in saying that my chickens may have had a dormant disease waiting for a bit of stress to flourish? Does this sound like MG or Coryza? They also have a nasal discharge and some have frothy, bubbly snot. The most noticable is the sound in the run - loud rattles / rales as they breath. There is no awful smell. Is it going to make any difference if I clean, disinfect and lie empty for a week and then start with the same system of my diff age chickens only being divided by a half wall? My chicken business grew very gradually from only a couple and thats why I have a very unorthodox setup that I would really like to work to save me breaking down the whole structure to put up separate houses. I have tried Terramycin for 6 days with no luck. Am now trying Triple Sulphur for 3 days? HELP!