Unexpected behavior

I was dumbfounded today when I went to pick out my Paint geldings left rear. He cowkicked me and sent me sailing. Granted, it was near feeding time (3:30) and he probably wanted to go in his stall and not out on the trail. I was horrified. I love this guy and have been working on developing a relationship of respect and trust. My gut reaction made me pick up a crop and wail on him. This was so scarey and he, clearly, was trying to show dominance. He never used to do this and I don't know why he's started now. I was so disappointed in him. What's going on???

I dont know how old he is or how long you have had him but it sounds like he is just testing you. I have had my paint gelding since he was a weanling and he still tests me from time to time even tho he knows he will never win because he never has. I think you must show your dominance and let him know that there will be a consequence for actions like that. Im sure there are people who will disagree but you need to be the dominant one, not him.

It is dominant behavior, he's basically telling you to "Hand over the grain and f*** off." But wailing on him with a whip is the wrong thing to do. You need to assert yourself as alpha at feeding time but in a way that he understands AND respects. So take a whip in with you and have him stay away from you. If he comes in without permission drive him away. You don't have to yell or be aggressive, just be ASSERTIVE. A lunge whip would be best, that way you have a longer reach if you need it. DO NOT let him in until he has a nice look on his face and he "gets the idea." Then allow him to come in and if he shows ANY signs of dominance (pinning his ears, lifting a leg, etc) drive him away IMMEDIATELY.

I agree totally with spirithorse. Also, i would do a lot of groundwork with him, even though it is boring. Teach him that you have your own space as well as he does. It takes a lot for a horse to back away from you and teach him to do that like this: When ever you are leading him and you stop, he probablly is standing practically over you right? He needs to know that he is in your space so bring your arms back and behind you as if saying "hey you are too close to me and I can kick too." Backing up is a very important thing. I'm basically saying that to show your dominance, you need to do some ground work with him and teach him that YOU are the alpha.

I agree with the two above posts that he needs to be reminded who's boss. I also would have done the same thing that you did when he kicked you, and I'm sure you didn't sit there and beat on him until he bled or anything. What would another horse (who is supposed to be the dominate one) done?
He sounds like the kind of horse that will forever randomly test you, you just have to adapt knowing this and know that you gotta be on your toes.
Hopefully he realizes now, that kicking the boss was wrong and you put him in his place and he won't try kicking you again. Good luck and try not to get too discouraged.