it was just verified by necropsy that we have Marek’s in our flock. What does this mean for my flock? I know it’s highly contagious and all of my birds have been exposed. But, how many birds should I prepare myself to lose? We have 6 hens that are under 2 years, 5 pullets that are 3-4 months and 8 chicks under 6 weeks. Once a bird shows signs of the disease, is it guaranteed to die?