give the smart calm some time, it takes about 2 weeks on the average to build up and get into the systems. if you want it faster in the systems, then use the paste kind in the feed regimen, if your on a feed regimen for this horse.
the thing about overly angry horses are they are hard to get into their heads for sure, and their memory of abuse is very acute to them. I have dealt with some crazy horses with a deep seeded anger issue towards humans. what worked for me, was putting that nasty and unsafe attitude horse (any age) with a very dominate herd leader for training.
I happen to be blessed with a strong dominate and physically reactive horse in my pasture that runs the whole show for very one. quick to turn and bite a unmannerly horse and trains my horse the appropriate distances needed for respect without me having to do it myself.
angry horse with leader only, removing all the horses from herd and letting those two stay with each other for awhile. I ignore the angry horse totally and go about my business with feed schedules or other things I do with my horses. I wait…and wait…
the day comes and it happens every time
, the angry horse will want to see, or join in what the other horse is doing with me. he gets curious. that’s when we go to round pen, all 3 of us. my trained leader does as he is asked of him and we go thru all the basics of ground work training. its a refresher course for my experienced horse and a watch what is going with the angry horse. I keep a whip ( not to hit the other horse, but to keep him distant from me, we are not friends yet, and we won’t be til he calms down). I only work on my trained horse and let the other horse be in the round pen with us for the first few times. then after that, I start moving my horses, both of them together, with walk, trot and canter, of course then we go into turns and etc. again, its a wait until the angry horse gets it and is doing just the walk, trot, canter correctly. there after I can touch this horse and not have reactions from them. but…the key is not to let them be your friend, they can’t be baby into this good behavior, and they don’t need any sympathy either. they need trust, and they have to work at it on their own, they can’t be made to trust you until they are ready, they have too much trash in their heads to do that yet, in the beginning. its their willingness, not yours. I don’t react to such horses other then the distance of my safety. they will tell me when they are ready to try trust with me.
but I always work them with other horse first. horse can show things that people can not to a horse that is scared, abused or angry with humans. your blessed to have young colt and this will work far faster for you then it has for my horses that have come in from rescues all hateful. most the horses I worked with like this were over the age of 5. young horses are far more ready to follow the leader then older horses are in this state of mind. so that part you are very lucky and can do this.
"There's a difference between interest and commitment. When you're interested in doing something, you do it only when it's convenient. When you're committed to something, you accept no excuses; only results." - Kenneth Blanchard