The horse probably isn't angry per say, just either frightened, over-excited, or disobedient. Happens fairly often. Great capture!

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Stock: ~equusstock
Prints: [link]

Probably not so much angry. That's more of an evasion-tactic than anything else. Scared, go up. Don't wanna work, go up. Sometimes if there's too much pressure, they'll go up to escape it. It's part of that flight-fight thing, too, going up on hind feet makes 'em bigger than the predator (snake, person, bicycle, other scary things).

I'd go with cranky, maybe... or tired.

Nice picture, though. You captured the movement pretty well! Sometimes rearing happens so quickly and then the misbehaving's over, before even getting the camera up lol

I agree with crushing. However it could be partial angry as well. There is still that possibility. I wasn't there so I can't see what the rigging looks like, where it is holding the horses head when he just stands. However it could very much be the possibility the horse was fed up with having its head forced into a collected position.

This is my personal opinion: A horse should not have such things on them any longer then a brief training period. An if it is there longer the horse should have been worked with it extensively with short periods so it can build the muscles. horses can get very sore when they begin to learn to collect since their muscles are not yet built up along their back. Wouldn't you be angry or fed up if you were forced to hold a position for long periods of time?

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So yes anger could be a possibility for the rearing but it could be anything really.

Nice capture. As mentioned above bucking is most commonly the cause of being frightened of or by something. The only time this has ever happened to me was after my horse had an incident where the last rider hadn't tightened the saddle properly and the rider and horse slipped under the belly so that horse got scared the next time we tried to saddle it and put me on!