Horses get very eager to perform the behaviors they ve learned. What is a cute behavior for a dog, can easily become a dangerous behavior in a horse. Clicker trained horses are eager to work. If you start teaching tricks before you have established a good working relationship, you can lose control of your horse. Tricks don t always follow the same rules of respecting space that other training exercises do.
Enthusiasm is a good thing, so long as basic manners are solidly in place first.
This doesn't mean that you have to give up clicker training. Quite the contrary. What I would recommend is that you go back to the beginning and reintroduce your horse to the clicker. You're going to teach him to touch a target. To do this you're going to put him in a stall with a stall guard across the front.