I am in rescue & with 8-9 dogs most of the time I run into all kinds of problems. I have had serious side effects from meds so- I have mostly gone natural.
My Benji got ringworm 4 years ago & then mange & bacteria infection. Got rid of the RW but for 4 years the mange & bacteria has come & gone every few month. Yes I tried the borax 7etc & it works but he kept getting it back. Finally I insisted on an allergy test.The vet said no way is that the problem but i INSISTED!!!!!!
Sure enough he had lots of allergies & mostly foods. I had him on a really good holistic dog food. BUT His allergies were beef-fish-barley oats- potatoes - sweet potatoes- lamb - grass- dust mites to name a few.
I immediately changed foods. He now gets chicken & rice only - no perservatives & no treats unless they are chicken. Guess what he has been great for 6 months - back to his old self. Yes he has scars & always will as he had it so bad he bleed all the time from the sores. But this was the culprit. So if you have skin problems check for allergies - ivemectin & antibotics for 4 years without stop. That's not good.
I also sprayed him with collidal silver & it also works.