Chicken negative for mareks, what is this diagnosis?

[Katieskerlong]

I got my results back from Texas A&M and what was previously suspected to be mareks by the lab directed ended up being something else. I think IBV but based off the report, what do y’all think?

 

[SamLockwood]

I would interpret that as either an infection, or exposure to a respiratory irritant that led to a fatal infection, or a congenital respiratory defect, or even all three depending on age and other factors.