We had an OTTB mare that would try to kick the snot out of you when you gave her her shots when we first got her. The first time I went against evrything I believe in and gave them to her in the neck and all at once to "get it over"...her neck blew up, she felt like crap for several days, certainly didn't make her better about having shots let me tell you. So the next round we squeezed her between a gate and a panel, took the needle off the syringe and while Dave feed her carrots I popped the needle in to her haunch where I like to five shots, let her settle down and then put the syringe on and gave the shot, 1 shot, 2 weeks later we didn't even have to do the squeeze between the panels and gave her her other shot.  no site reaction, no reaction of any kind and when we sold her 5 years later you coudl give her her shots with out taking one.