I am moving to a different barn and the stalls there are open, is it safe & ok for horses to be able to stick their heads out? I personally think my horse will like this but someone else told me it is dangerous.
Open as of in...the top partion not being there? I see no problem with it as long as your horse isn't a biter...nothing worse than having a horse lunge at you with bared teeth when you're walking by! The only problem I could see with it is that if you leave anything (halters, leads, brushes, bridles, etc) by the door, he might get bored and chew it- or if he's a lock picker, you'd need an extra latch at the foot of the door.
Yes, the top, so he can stick his head out. Good point about picking the handle! It would be hard to imagine a horse trying to jump out...but I suppose it could happen. My guy is pretty well behaved in general so I suppose I shouldn't worry!
My horse wigs out if he is in a stall without an opening. As long as you don't leave things where your horse can get them you shouldn't have any problems. I suppose they might bump their heads on the way in or out, but they learn very quickly exactly where the edges of their stalls are.
As long as the stalls aren't open between horses. The height of stall walls and doors often force a horse to stand in an unnatural position with his head higher than normal. This doesn't allow it to truly relax because in the lower position he can't see the other horses.
All the barns I've been at have done this. It isn't a big deal and is probably better for the horse. However, if you tack up your horse in cross-ties instead of in it's stall this can bring up some interesting issues. Try to learn which horses are friendly towards other horses (and humans) and which would rather be left alone. And of course some horses just plain hate certain other horses. So be careful with that and of course watch for nippers.
I don't really think it's dangerous, as long as the door is sufficient in height. There is the off chance that they can get objects into the stall, but if nothing is left for them to get, that should not be an issue. Amber did used to pull her bell boots off her blanket rack and kick them around for fun when she got bored, and that was annoying, but not dangerous to her.
If the openings are close by the other stall, there may be some nipping conflicts with other horses though...but again, that's not terribly dangerous. I'll put it this way - there are circumstances that can make it annoying, but it wouldn't turn me off of an otherwise good barn, and it wouldn't factor in as a turn off if I looked at a bad barn.
There are both open and closed off stalls where I board. My QH adored her corner stall that had 3 half-height walls and then the back wall was fully enclosed. When I bought my gelding, I put him in her stall and he couldn't handle it. He was a nervous, fidgety, shaking wreck, so my trainer moved him to a stall that where the front, back and 1 side have are solid wall 2/3's of the way and bars the rest and the other side wall is a half-height wall and he loves it.
The only bad thing I found with open-stalls is that if all the horses are in the barn, the lesson pony likes to lean out of his stall, grab the cross-ties and harass whichever horse is in them. He's not above harassing the farrier either. Oh and my QH leaned over one night, snatched her blanket off the bar and had a great ol' time shredding it.