Not locked. Tightly-closed doors were removed in the steam version, I assume because they were the single largest cause of FPS death by a huge margin, so you won't find the option there. They let creatures who can open doors through but not creatures who cannot, which is most animals.
Also,
Sorry for my ignorance but when you say "tightly-closed door mishaps" what does that mean?
With a built door, you have the option to close it tightly so that animals cannot go through it but dwarves and other sapient creatures can. However, animals don't treat tightly-closed doors as walls like you might assume, but will instead use the same pathfinding as creatures that can go through them. This results in creatures clustering around tightly-closed doors, unable to get through and spamming the same attempted pathfinding every single frame. This might not be a problem with one or two doors that get the occasional pet stuck on them, but if you have, say, a room full of dozens upon dozens of turkeys all fighting to get through a door, or if every single one of your doors is tightly locked, that can cause problems.
Not every frame, more like every 10 frames. Pathfinding is very, very slow, it's just not done often.
