I wish I had found this board sooner and learned more about bio-security. I thought I was an experienced chicken mommy. Ive had my flock of McMurray hens for 3 years now. No problems & healthy birds even bought some hatching eggs last year to see what would happen. Out of 14 eggs stuck under a broody, we got 10 live babies. But I digress In January of this year a co-worker of mine read an article about how an area humane society had seized over 500 chickens the previous November from a neglectful owner. They had been nursed back to health & were now up for adoption. Me being the sucker and wanting a few more hens took the trip down to see them. They had been in quarantine for 2 months already, given medication, inspected by a vet, etc. They looked healthy & were in good weight. (They look like they might be sex-linked hens.) I decided to adopt 4 of the friendliest girls. I was told to quarantine for a month & not eat any of their eggs to be sure the antibiotics were out of their system. The new girls spent a month in a separate pen (far away from my coop) without incident. They ate well & expressed no symptoms of any illness. After 30 days I moved their pen (a dog x-pen) into my coop to minimize any fighting. There were some squabbles through the bars, but after a week or so, everyone calmed down. About a month after moving the new girls into the general flock, things began to happen. Sneezing, nasal discharge, swollen shut eyes, gurgling & coughing & cawing (like a crow) of my established flock. Over the course of 3-4 weeks in March, 6 of my 15 original, 3 year old McMurray birds died. Almost all the birds had varying degrees of the symptoms, but recovered. None of the 4 adopted birds showed any illness & none of the hatched chickens died either (they had no vaccinations like the McMurray birds did). It took several months, but all the remaining birds have since recovered & are now symptom free. But Im now playing the, could have - would have - should have game with myself. I feel terrible. I feel stupid. Im angry at the humane society for releasing these birds. I feel guilty. Im even angrier at myself though for not doing anything. I was afraid of what reporting the illness would bring on me & my backyard farm. Im in a dilemma. I want to get more chickens, but now Im concerned that my flock are carriers of some disease. Ill never introduce adult birds again (lesson learned). But Id like to try hatching some eggs again under a broody or buying some chicks. However, Im afraid of infecting any new eggs/chicks with something if my hens are now carriers of. Does anyone have any idea what they might have had? What should I do at this point? Should I notify the state? Im wondering if it is too late to do anything, since the birds are now normal. Im just afraid of opening a can of worms. Please dont give a tisk tisk speech, as Ive already beaten myself up enough. I just dont want to make any more mistakes. Thanks everyone!