The area is probably infected. You should take your dog to your veterinarian for antibiotics. In addition, I would also do the following: I would give Derma-IonX which is an oral homeopathic product stimulates the enzyme systems in the body which reduces inflammation , promotes healing of the skin and helps with assimilation of nutritional components in diet and supplements. The supplements I use along with it include Canine probiotics, vitamin C, MSM, and Omega 3,6,9. Together with Derma-IonX it produces a synergistic effect for a faster response. I would also suggest that you give your dog only filtered water for drinking and bathing if your water contains chlorine or fluoride. For the dietary modifications you might want to try a grain free diet for a while.
Defendex shampoo which is nontoxic washes away debris and soothes the skin. Using these can make a real difference in skin health.
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