Hi, sometimes the dog will scoot because he has been groomed. I have had vets who tell me that if the dogs poop is firm then his body is taking care of expressing the glands. I have been told that once you manually start expressing that the dogs body then stops doing it on its own
Zander is 2 and I've never had to do this for him, same for Jazzie so proceed with caution and informed.
Here is a link to some info about clearing the glands ....
Dog Anal Glands - LoveToKnow Dogs