My semi longhair tortie has a matt on her lower back and she's had it around a week now. We've tried combing it out and it won't come lose. I've read bathing her or washing the matt will only make it worse and the best option is to cut it off. Any opinions? She's never had one before and shes 4 now so I'm a bit shocked but it does appear to be where I imagine it would be difficult for her to groom herself, plus they all are getting their fluffy coats so wonder if it could be due to that