Lucy has demodectic mange

Hi there,
I wanted to share my girlfriends story about her beloved dog Lucy, in hopes that maybe someone here at DG might have some new or more successful treatments for her pets condition.
It makes me so sad, everytime she tells me all the treatment she goes through and it never gets any better.
Lucy is a Shepard cross and she is approx 11 years old.

This is her story:

Lucy has demodectic mange also called "red mange". It is a non-contagious skin disease caused by a tiny parasite that lives in her hair follicles (I'm getting this from the handout the vet gave me). Lucy was found as a puppy by the neighbors. She's had the mange since they picked her up and then we took her when they couldn't keep her. To treat her when she is infected, I give her Ivermectin (liquid) 2ccs per day. If she has open sores, I give her Prednisone. She's also on Deramaxx for arthritis, vitamins, and Prozac for doggies (although I've been leaving that off lately and she seems fine). The kennel bathes her in Sulfoxydex shampoo to help clean out her follicles when she has a bad infection (she won't let me bathe her). Please let me know if you run across any miracle cures or even a healthier diet to feed her to help prevent this.

Thanks so much for any and all suggestions