All dogs and some humans for that matter carry the demodex mite. The difference between dogs that show symptoms and the dogs that don't is immune system. Dogs with healthy, strong immune systems can keep the demodex population at bay while dogs with compromised immune systems can not. Did your vet tell you if your dog's demodex is generalized or localized. Generalized is more serious. With either they can make a full recovery, but generalized is more serious and sometimes harder to treat.
Dealing with a breed (pugs) that suffer from demodex on a regular basis I truly believe that diet and supplements can play a huge role in boosting the immune system. I have been lucky enough to completley avoid demodex in my household, but a lot of my pug friends have not.
I would recommend you seek out a very high quality food like California Natural, Canidae, Eagle Pack, Solid Gold or Innova. I would also recommend you try using Solid Gold Life Exxtension as a supplement for the immune system. You can find info on this at
www.solidgoldhealth.com.
I also personally feel that Ivermectin is a much more effective treatment than Mitaban dip.
Best of Luck and welcome to Chaz.