When I first got my chihuahua last year she was 3 months old and it was winter. she wore sweaters alot because it was cold and she was tiny. once it started to warm up she stopped wearing clothes. now its getting cold again so i started putting sweaters on her again. i noticed that her hair is breaking of in a post on her upper back. im not sure if it has to do with the sweater or not, but it just started after she had been wearing the sweaters for a couple of weeks. she scratches alot when i take the sweaters off her. could it be just the sweater or possibly something more serious? i just thought i would get some advice before taking her in in case its just the clothes. she has course hair and its not exactly falling out, more like breaking off. thanks!