I would check with the vet first but expect he/she will advise against it due to the dog being able to lick it off. Also, determine why the hair is falling out (could be hormonal or related to another health condition). If simply due to dermatitis and skin sensitivity (appears that way in the pictures), I have had success with natural pet procucts (sprays and baths) that include tea tree oil or colloidal silver as well as oatmeal (which is soothing) and are targeted for allergy and skin problems in dogs. I have a golden as well and have successfuly treated many 'hot spots' with these products. You may also want to add doggy supplements for skin and coat which include omega fatty acids (just like for us). Good luck!