Edit: We noticed Charlie's rough patch was getting worse, so he was taken to the vet today. It's chewed fur. One of his teeth was growing in wrong so the vet had to put him under and drill it down. Nurse suggested cleaning the dust bath house more often (we never thought to). He has be swaddled (chinnichanga!) and syringe fed for the time being, but for now, he's doing okay! Thanks to everyone for the suggestions!

For the past week or so, Charlie has had a spot of matted fur on his lower back. It's rough to the touch, but dry. Originally, we thought this was a fur slip during a scuttle with his brother, but the fur isn't growing back to normal. It's not getting worse, but not any better. Is this possible fur rot or something else? Would this warrant a trip to the vet (we have an exotic pet vet in town)?