I've owned her three or four years. Last spring and this spring she isn't shedding normally. The hair is falling out faster than it grows. She looks like a baby bird. What could cause this? Can I prevent it next year?

We have a mare that does this but her dam did it & her granddam did it. Hers only last about a couple of weeks & then she has a beautiful shiny coat 

Do you have any pictures of her? How old is she? 

I had a older gelding in his 20's that would shed out till he was balding in spots, then after a couple of weeks his hair grew in and was shiny as heck. I have another gelding that turn 20 this year and he grows his winter coat befor the others out here and he sheds really early too but he dont do the balding he just sheds before every body else , I was really worried about him when we had that horrible weather with snow and the freezing that went on for days since he was shedding out during this time but he did fine, he looks like someone has been polishing his hair everyday, hes so slick and shiny and everybody else is about finished shedding.  

Horses just are different not everybody sheds out the same. 

I'm embarrassed to post pictures. She's naked. I'm blaming it on the Buffalo gnats. Last year was the first years we had them. I keep her sprayed down. Bless her. This is awkward.

I hsve several that look like that. The hair will grown. These are mares that are scheduled to go to west Texas to be bred. I just don't worry about