Many dogs have skin issues either from allergies, hotspots from itching/chewing or chewing from boredom, etc.
Most vets will put your dog on steroids which is not good for them long term.
I prefer the holistic approach when possible and have found a few things that work well.
One is a salve of Comfrey and St. Johns Wort compound from www.mountainroseherbs.com
Another is Quercetin and Bromelain. I use this product giving one per day:
Vitamin C in high doses (to bowel tolerance) works well too. It makes the adrenal gland produce natural steroids which work as a natural anti-inflammatory. Slowly increase and watch for bowel intolerance. I have given as much as 6000 – 8000 mg. daily split up in 2 meals.
The rule of thumb when using human supplements for a dog 50 – 90 lbs is 1/2 the adult dose. For small breeds or puppies give 1/2 the child dose. (Vit C is a water soluble vitamin so the body will flush what it does not need/utilize)
Some dogs will have allergies to certain foods so if you suspect this you need to do elimination diets. Fillers can often be the culprit (corn, wheat, etc.) but sometimes it is the protein source in the dog food. You can do allergy testing to pinpoint the culprit whether its food or environmental but it can be costly.
Years ago I had a dog allergic to corn. Switched to a kibble with no corn and it solved the problem. I watched her eat an ear of corn off the stalk in the yard one day and within 24 hours she had a huge flair up so for me it was easy to figure out. Years later the same dog needed specific food for kidney failure and it had corn in it but she never had a flair up which tells me she outgrew the allergies just like children can.
If you are unsure about using human supplements for your dog consult with a holistic vet.