We really had two groups of chicks affected, both from the same breeder, obtained two months apart. In Group 1, we lost an older cockerel and pullet, with the pullet at point of lay. We had also lost several younger (2-4 weeks old) chicks from this group but since they were found dead and not necropsied, that could have been something else. We have 4 surviving hens and two roosters from this group. Group 2 was the worst hit. There were 2 cockerels and 5 pullets bought as 3 day old chicks. One again died at 2 weeks, no necropsy. Of the remaining 6 chicks, three looked great and three were small and growing slowly. They had intermittent, mild pasty butt that would come and go. All were on medicated feed to prevent coccidiosis. At two months of age, the three stunted chicks died within a few weeks of each other. Coccidiosis was found in the first of these so we gave high dose amprolium. The next two died a few weeks later: no coccidiosis but they had Marek’s tumors. At this point the three healthiest looking birds: two pullets and one cockerel remained. One pullet got to 6 mo old, then died of Marek’s without ever laying an egg. She had been in the nest box recently so we thought she was about to lay. The second pullet started laying at about 6 mo old and died of Marek’s two weeks later. We still have the one surviving cockerel, he’s a year old now and appears healthy. So, we seem to have the most problem as young chicks, at 2 months, and as they begin laying eggs.
