My older dog is not a yorkie but I hoped maybe someone on here would have some advice for me. She was recently diagnosed with a skin infection and the doctor seemed to think that the infection caused some demodex. She was on a round of antibiotics and it has improved the skin infection but the demodex seems slightly worse. Apparently, the normal medication they would use to treat this, can not be used on Collies. The vet seems to think that this kind of thing happens with a compromised immune system and there is a strong possibility that it could be Cancer. She is doing a test first to rule out a fungus of some sort but doesn't really think that is it. Does anyone have any knowledge of demodex and if there is any natural way to treat it? And does it happen frequently with cancer?