There are a few questions about closed doors, but I feel my question has a bunch of different angles which makes most replies inapplicable.
One of our three cats has a big issue with going to the vet. While normally a very calm cat, catching him to put him into the box turns into a literal persistence hunt, all the tricks to get him in the box won't work until he just gives up from exhaustion and we can pick him up - but even then only with gloves or your hands will be severely cut, as he puts up a fight for his life. This is also the reason why we need to close the bedroom door when we want to catch him, because otherwise he will hide under the big bed that we can hardly move and therefore cannot catch him.
This has caused him to associate a closed bedroom door with the "torture" of getting caught and going to the vet. While the door normally stays open, my wife sometimes gets up much earlier than I do and will have to close the door for 1-2 hours or I cannot sleep anymore. With every visit to the vet the behavior gets worse. Currently we are at the stage where he will cry (yell) non-stop at the door, attempt to scratch it open, pounce into it without interruption, which means I can now choose not to sleep because my wife is getting ready for work with the door open or because the cat is crying his soul out...
Are there any recommendations how we could approach this situation?
EDIT: Funnily today's vet visit was super calm, he hid in a corner, walked into the box after a few minutes and has been super quiet even with the bedroom door closed. Maybe he read this post and was embarrassed...