rabid_child: " you don't need to explain anal glands via links"
Not everyone is as educated about dog's anal glands as you are.http://www.marvistavet.com/html/body_anal_sacs.html
rc: "ETA: Its liquid, there is no scooping to be done."
All the links say that while its normal state is liquid, it is very common for the liquid to accumulate, and harden. Yes, this is when animals start dragging their butt, "scooting" -- presumably because the swollen sacs itch. When dragging, the dog may or may not be successful at expressing some amount of hardend anal gland secretions. While whole globs may not come out, certainly a thin smear is not at all unlikely.