I recently lost two pullets, one I culled when she had a progressive paralysis in her leg without any obvious cause, the other lost her balance a week thereafter and I culled her too. They were 18-20 weeks, so pretty likely mareks :cry: I had a live chicken from a friend this summer, only living animal I ever introduced in my flock. I am sure she brought it with her because the girl who gave her to me lost some young animals a few months thereafter. So now I have a coop with 6 hens, 4 are 2 years and 2 are 7 months. They all seem fine but they lay very poorly. The have been indoors the last 3 months (we live very far north) but before that they were all free roamers. Also I have had all the poo and stuff I clean from the coop right outside of their pen. I have 4 other chickens (8-9 months) living another place on our property. I have the fodder seperate but I have used the same clothes when tending them. I do not have any vaccines available (It is not sold to hobby breeders in my country), or that would have been my choice. So I am actually planning on culling the flock of 6 hens, changing the soil in the pen, changing the floor of my coop, washing with 1:100 Virkon S, paint the walls, wash again and then leave it in the bitter cold for the rest of the winter (3 more months..). But will it suffice or will I just make alot of work and then have my new chickens infected with virus again? I have read they survive for years those nasty bugs... Is it likely or unlikely that my seperate chickens has it? They seems very healthy, but off course they were maybe to old to show clinical signs of disease? I can also mention that it is pretty cold here, I guess the viruses wont survive outdoors in snow and ice, a few times of thawing and refreezing would do it for them wont it?