I need some natural remedies to help my horses skin allergies!?

Vet said my mare is tooo big for steroid treatment. I want to know what has worked on other horses. She gets bad hives from the bugs and itchy skin and hair loss from pollen or vice versa. She gets when the weather permits nice aloe baths and medicated sprays on her skin but it only helps a little. Whats something she can take that has worked with your horses?? I have done a ton of research and there are so many natural remedies out there I don't know what will actually make a deference! THanks