I had six hens. I bought a EE hen ($30) from someone in the Orlando, FL area because I wanted blue eggs. I have only had hens for about a year. I did not know all EE's did not lay blue eggs. I found out the hard way. She just started laying and its BROWN!! On top of that she gave my entire flock and upper respiratory thing. The state is coming to test my flock of 7. After calling they told me it is probably MG. I did not lose anyone, at first sign of rattle, I immediately came to BYC and did LOTS of research. BYC is awesome!! Symptoms: rattle while breathing, some gasping, lethargic, coughing, I got a soft shelled egg, laying dropped off. Acute onset and wiped through my whole flock in two days. No swelling or bubble in eyes. I started antibiotic injections and VetRx before second hen started with symptoms. It went through all six hens, never touched the new EE which i quarantined for almost three weeks thinking I was being a good chicken mommy. NOT Two of my hens are only 22 weeks and have not started laying. Bought them as one day old chicks. Four of the hens are a little over a year. I have a RIR, two leghorns, a manchester red, buff orpington, and a black chicken the feed store said was a sexlink and not to forget teh EE. Now I have inhaled everything I can find on the net about MG and IB. It seems hopeless to keep any of this out of your flock if you free range, which I do. I have had chickens for one year and already encountered this as well as what I thought was bumble foot. It ended up not being that. Just a puffy foot from injury. I wish I knew about all the chicken diseases BEFORE getting chickens. I love having them but I thought it was going to be easy. Feed them healthy non GMO food, free range, worms, keep coop clean, fresh clean water every day and I would get eggs in return. I hope things will calm down and we can get back to enjoying having them again. Chicken TV is the best. I still want a chicken that will lay blue eggs. Americana seems the best route. But, I am at the understanding that I might not be able to bring in any more hens until these have all "gone" If anyone can give their opinion on this VERY confusing issue, it would be much appreciated.