If you have a chicken acting strangely, like putting their head between their legs, jerking their head, skygazing, or acting paralyzed, it is possible they have a selenium deficiency. This can happen at any age. Just get the suppliment in any store, grind it up and add water. You should see improvement in a few days if that is the problem. Silkies seem to get this often. I know when I was looking for a cure, I couldn't find this information anywhere, another breeder told me. Good Luck!