Last year I noticed my dog chewing her feet or constantly licking them. At first I thought maybe she was being obsessive and would try to distract her from licking by giving her a toy but it made no difference. I mentioned it to my vet and she said it was a possible allergy to a treat I was giving her. Through trial and error I noticed a big change and found out my dog was allergic to duck. Everytime I gave her this certain jerky treat she would itch. By paying close attention I was able to eliminate this particular problem. Many dogs have simillar allergies but their causes may be different. Scratching ,redness of the skin or sore spots may be caused by dust mites,dust,pollen or food. It is simillar to” hay fever” in humans.Since dogs ingest these allergens they show up on the skin instead of in the sinus area. Constant licking can create sores and yeast spots making your pet very uncomfortable and possibly in pain. Treatments for these allergies may be a special diet or medication to reduce the symptoms. Pay close attention at what may trigger these episodes and contact your vet.