I have this again this year also. In my book I put the reason for this behavior in deer. I had this problem years ago from a tame doe and tried every thing and ended up putting her away. Last year I had a doe doing this to fawns but not as bad as the earlier one. This winter I have her yearling doe doing it to my smallest bottle fed fawn . I believe this is being passed down in this bloodline . Is there a answer ,no we haven't found a solid solution and may never be able figure it out. Unlike the doe years ago that pulled out her own hair and anybody that would stand still for her, these recent ones are not pulling
out their own. After 28 years raising deer and trying hot pepper , nerve pills and many other concoctions , I think it is a nerve condition that happens in a few rare deer. Some day somebody will find the answer and a solution. Being a deer farmer you can be sure to expect the unexpected as It will happen.