we had an outbreak of what we are assuming to be infectious bronchitis in our 2 year old laying hens this past August. They were treated with antibiotics and all were better. their egglaying has diminished alot and i am going to butcher all and have my new batch in the spring. one hen is starting to hack a little, she is also very obese. could infectious bronchitis be back. can i eat my hens if they have had a sickness in the past?