I have lost 7 serama juvenile chicks over the past 3 weeks. The first 2 were roosters, found dead 2 days apart. No previous symptoms, no apparent injuries to the body. I thought perhaps the adult rooster killed them but as stated there were no injuries, no blood. A few days later I found 2 dead, a rooster and hen, same thing. Two days ago, 3 dead, a rooster and 2 hens. These 3 did act lethargic the day before, but no eye drainage, no cough, sneezing, wheezing, etc. I put antibiotics in their water and gave them oral vitamins. None of which helped as they died. I have 4 adjoining pens and the chickens in my other pens are fine with no deaths. I don't understand it, they look so healthy, beautiful feathers, good weight, bright eyes. Then within a day they are dead. Any suggestions or advice. Anyone with Serama experience? Is it a breed problem?