I have had a small flock of chickens on my farm for 16 years. I have bought and sold birds from and to different people over the years (not a ton) and never had problems with disease. My birds are in movable houses surrounded by electric netting until it snows then in our big building (60'x80') for the winter. This fall I bought 8 nice yearling hens from a lady...3 silkies, 3 EE's. Quarantined for 2 weeks then introduced into the group. Everything was peachy until it got really cold. In 3 days everything I had was sick except for the new silkies. Two of my older girls died and the vet necropsied and did a respiratory panel. Positive for ILT...Hoy Cow, I've never even heard of it. Since then I haven't lost any birds, we went into serious supportive care mode but, I have gotten two different opinions from vets. One...birds will always be shedders of the virus even if we vaccinate and will infect anything they come into contact with. Two...once it warms up and everyone is 100%, vaccinate and they will not be able to infect other birds. Very different meanings for us. Sorry this is so long but, nobody wants to talk about ILT or admit to having it on their farm. Any help greatly appreciated. BTW several of our birds are my children's pets and my oldest just started breeding Pilgrim Geese.