Cleaning the anal glands the anal glands will be full
Not the best of jobs for the vet a finger up the dogs bum to sqeeze the glands out.
Only trouble it might have to be done often
actually it can be done by squeezing from the outside and the inside, but if you do it from the outside there is a big chance it will squirt out and hit you and it wont normally empty it fully, if you just stick your finger up the bum tho it a bit gross but it only ends up on your finger and the tissue when you wipe up after.