
Hi John,
First of all, look at the diet. What are you feeding your dog on? Remember "you are what you eat"! I would look at upping the amount of oily food, I bet your dog has dry skin all over? I personally feed my dogs on BARF and they rarely have any health problems. My dogs breed is renouned for dry skin but hasn't suffered yet in his 2 years of living with me.
Ask your vet or consult a natureopath as to what to do, otherwise you will keep suffering the same problem , good luck :)