Your horse most likely reacts this way because he associates deworming and shots with uncomfortable or painful experiences. Therefore, it is necessary to establish a routine that is as comfortable as possible for the horse. In the case of deworming, other methods besides using paste may be more successful. There are deworming products that you can topdress on your horse’s feed that will make deworming a much less stressful process. Also, sometimes if you will take the dewormer tube and rub it over the side of his lips until he quits throwing his head, and work very slowly with him, he may get better for administering the dewormer. Another option is to put something such as corn syrup into a clean syringe (with no needle) and offer it to your horse at random times when you are not in a hurry. This may make the horse more interested in taking the paste since it has a pleasant taste. Often horses react when we either try to "hurry" or "fight" them to get things done. A slow and calm approach,with no punishment but also not giving up, often gets the job done.
As for giving shots, it is important to make the experience as comfortable as possible by approaching the situation calmly and slowly. If your horse starts getting worked up as you are about to administer the shot, move with the horse and continue the injection when he calms down. If he is overly anxious, he may need to be distracted with a twitch while giving the injection. Certainly, find a more experienced horse person to assist you and work with your horse if you are not comfortable dealing with these methods on your own.
