Looks like eczema. You can boil water with pepper and salt. Basically, put a handful of peppers in two bowls of water, which is generally the size of a bowl where rice is eaten. Boiling a bowl of water is almost enough. Filter with gauze, put it in the refrigerator, and apply it to the affected area of the dog in the morning and evening. Where there is a strong place, you can wash it with hydrogen peroxide and then dip it in Chili water.