I have noticed a small area on my Persian's back which looks like she has lost a lot of fur which is now growing back. It is not lumpy or itchy, red. She gets regular flea treatment with frontline. Does this sound like she has been grooming herself excessively and am I right in thinking this is a sign of stress? I can't think of any recent stressors. I do have another cat who she bulies a bit and is not too keen on but he has been with me for about 18 months. Help appreciated.