I feel it's better u take ur pet dog to nearby doctor and if he does skin scrapping tests and other diagnostic tests with the skin scrapping or hair pluckings, they can exactly diagnose the problem that it's due to mites or fungal or bacterial infection, that gives the confirmatory diagnosis and can cure ur pet soon, Thank you.

These kinds of skin related issues happens due to many reasons. It needs to be checked either online or offline to find the possible cause. With minimal information, it is not possible to give a solution for this issue.

Skin infection s can be due to various reasons.. External parasites,food and environment allergies, infection s..it's very difficult to give treatment suggestions..pls consult a vet offline or online to get Diagnosis and treatment options..