Is there a doctor in the house?

[scooterII]

Is there a doctor in the house?
Hi It's Scooter's owner here. I'm new on this site & am trying to navigate the best I can here. Scooter is an 11 yr old female spayed DSH. She has soom fur matting. Am I too agressive in grooming here if I pull some fur out by hand. It doesn't hurt her. But Is it odd that soom spots show faster than normal fur growth, so I ppull some out. I know I over did it once on the back of the head. There's a small bald spot there now. Could it be a sign of some internal infection, as well? She behave's normal. Any fedback is appreciated.