To know what the cause of the skin irritation is one would visit the pet's veterinarian who can culture or look at sample under the microscope. If you have fleas it can keep the skin irritated because the pet usually develops an allergy to the flea and it only takes one to get the reaction going. Some people will use organic diatomaceous earth in the house and on the pet which slowly kills the fleas; but you need to be careful to avoid breathing the dust in. I prefer to use Frontline spray on the pet because it works faster. I also like to bathe with Defendex shampoo to soothe the skin.
To help improve the skin I usually use the following the things. Derma-IonX which is an oral homeopathic product stimulates the enzyme systems in the body which reduces itching and 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.
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