Our cairns get their 'done' at least once a year. And Sophie had one rupture right through the area next door to the 'back door', if you know what I mean. It was a huge infection danger so we had to keep it clean - ugh what a chore.
Anyway, the glands are supposed to naturally drain when the dog has a BM, but sometimes, it just doesn't work out that way and that is when your dog will begin scooting (or gragging his behind) along your nice clean carpet. I call this the "Chuck Berry Dance" when my pups do it.
What a delightful morning topic. Hahahaha