One of my yorkies does it all the time (scooting on her butt). She goes around in little circles. I have taken her to the vet and he expresses them, and then she's right back at it. I could take her once a week and it wouldn't be enough. And, I don't want to do it myself. I draw the line right there! lol
I don't mind cleaning their butts, but not "expressin" those glands. So, she just does her little "helicopters" as we call it. I hope it's not hurting her. I don't think so. She's healthy and doesn't have anything wrong with her. ????