A prion disease (transmissible spongiform encephalopathy) is a disease caused by prion aggregations. Some prion diseases include bovine spongiform encephalopathy (mad cow disease), kuru, scrapie,...
Loss of feathers can be caused by several things. Feather pecking is often the usual culprit. When a hen house / roost gets too crowded, the hens peck out the feathers of the chicken next to them in...