I agree - don't let any growl go undisciplined - just a touch and a word or sound that you would use to correct. My Ginger does that and is corrected every time but she still does it - she has fear and this might be your dog's problem also. Ginger will jump if touched unawares but then is ok - she is just so fearful. But I don't try to soothe her I correct her - my word is "out" and a touch. she knows - they are so smart.