I have a question regarding infectious coryza ( chicken cold) I bought 2 new chickens ( a rhode island red and a fayoumi) on the 29th 0f August. They looked to be in good health.That evening we put them in with some of our other chickens. Two days later I noticed my partridge cochin pullet breathing very strangely( opening and closing her her mouth and taking long frequent breaths). It was during the very hot spell so my partner Richard thought it was due to the heat. I, however had spent most of the hot summer watching them and had never seen the constant opening and closing of the mouth during the heat). That same evening she was still doing it and now so was my gorgeous golden laced polish. At this point I was very concerned. In the morning we found them both dead Not only were they both dead but now our dark brahma cockerel was showing the same symptoms. Still believing it might be heat related we brought him into the house. By the next day both of his eyes and sinuses were swollen. It got so bad that he looked like a hammerhead shark. At this point I decided to do research on the internet. I discovered that all of the symptoms were that of infectious coryza( a very deadly and infectious virus that is passed quickly throughout a flock with an incubation period of 1-3 days) Fast foward two weeks: TODAY- we have had 14 sick birds and lost in total 9 chickens , including one of my gorgeous phoenix roosters and our dark brahma cockerel. Still on a daily basis we are finding new chickens exhibiting symptoms. We have been separating the ill from the apparently healthy and it appears a few of the sick may survive. This has been disastrous for us in many ways. There is definetely the financial loss considering how much we spent on purchasing the birds . Then there is all of the hours we spent taking care of them and the cost of feeding them . Then there is the emotional toll since we were attached to our birds. But mostly there is a loss of trust and a sadness that people could knowingly sell birds that could pass on this disease. Here is where my question comes in( FINALLY). Since all of my birds were healthy and the last time we had any new birds enter the flock was a good 4 weeks prior ,and symptoms ONLY appeared 2days after the two new birds entered the flock ,should I assume that they brought it in? I have read that apparently healthy bids can have been sick with the illness , recover and then become transmitters. This means that all of my birds that have come into contact with these birds and those that recover must be culled. Even if they recover they will be shedders of the disease for life- sure I could sell them to unsuspecting people but that goes against my morals and principles and I would never put anyone else through the trauma that we are going through. I have defineterly learned from this experience although it has been a very expensive lesson. I would advise anyone to be EXTREMELY careful when buying new birds and adding them to your flock ! From now on we will only buy day old chicks or fertilized eggs . I think I was too naive in believving that a bird that appeared healthy in fact was and that my biggest worry was mites and worms.... Unfortunately I will never trust anyone else selling birds again...which is very sad . If you are still reading this thankyou for reading. Sandra Thankfully I do have two other coops and runs with about 20 chickens who have not come into contact with these birds so I am going to focus on them and hopefully build my flock back up.