[anonymously]

“I don’t think the problem with anal sacs is that serious, vet expressed twice so far, but I suspect that maybe there is more than one thing at work here.”

Hmmm, is that your opinion? You may want to ask the veterinarian that has examined your dog what he thinks? After all, I assume he went to school for 8+ years after HS (as much as a medical doctor). Maybe he knows something.