I have a 14 year old female shitzu that has recently been licking her butt a ton. When I try to get close to her rear, she will either turn away from me or run and hide. When i was giving her a bath the other day, when I was trying wash her rear, she yelled. I was able to get a quick look when I was drying her off before she ran from me and there looks to be a white sore on the side of her anus. Would an antibiotic ointment or an antifungal ointment help?