So, I just made a little test in the game and it unfortunately doesn't work for giraffes, elephants, rhinos and hippos. For the giraffes, it make sense because they are taller than the frame but the others should realistically be able to go through it. The problem is their insane hitbox. What's funny though is that elephants and rhinos put their head through the PVC and even make the curtains move with their head. But they never go through it. But it can look like they are inside and thinking about going outside before changing their mind