Demodex on dog

Question
Hi,
I have an Australian Shepherd, 1yr & 2mo. old. At 8 mo. he was diagnosed with demodectic mange. He had hair loss on his face and front paw. We chose not to get the mitoban dips and because he is a herding dog, he couldn't get the shot for mange. So we put goodwinol (sp?) cream on the spots. They cleared up, but 2 mo. after that, he developed similar spots above his elbows. One side cleared up on it's own. But the one front leg doesn't respond to anything. It has been there a while and hasn't gotten bigger or smaller. It is a hairless spot that is red and crusty.
My question is if there is anything else I can try to clear up his spot. I've tried the ointment, neosporin, aloe & vit. E so far.
And also, since he still has this, is this something that will stick around for the rest of his life?
Thanks,
Candy

Answer
The Goodwinol is good for spot treatment of demodex.  The problem with demodex is that it is all over the body.  Letting it go without systemic treatment will only make it worse as the mites tend to burrow out of the sebaceous glands, where they live, into the dermis, where they cause scarring and infections.  The amitraz in Mitaban has the ability to penetrate into the sebaceous glands and kill the mites.  I think you made a bad choice in not getting the dog treated properly. That is the only approved insecticide right now.  It works well.  I treat about 50 cases a year with it, and only on rare occasions do we have any problems.  I do not use Ivermectin because of the expense and the side effects in some dogs at the high doses required to treat the mites.