Abby has had some bare patches on her skin (on her back) since we got her. But as she has gotten a little bit bigger, the spots seems bit more apparent as those areas stretched a bit. Has not gotten worse really though. Initially I thought once she was on a good diet, they would go, but she's been on Canidae for about 4 months now and they are still there. Anything I should be concerned with? The vet didn't seem too concerned during our initial appointments and commented on how her coat had improved between the first appointment and the next. They don't seem red or irritated at all and she doesn't seem to fuss with them. Any thoughts?