Any chance of coccidiosis (sp) very sudden deaths, start of lethargic then next few hours death, turkeys are a nightmare to rear until 7 weeks anyway, but still doesn't make their deaths any easier
Can see blood in the faeces if coccidiosis, this is easily treated with coxoid in the drinking water for a few days. Need to give me a few more details of your pen and some symptoms if any, if it is anything like us the changeable weather is having an effect and the daft poults sit out in all weathers, have to put them in every time it rains.