You give it in the vein. I had never given an IV shot, but the vet showed me how and I got it pretty easy. I'm glad I learned, just in case I need to give a shot of Banamine or something like that.
Do you have a marker? I watched and my vet seemed to be right at the crease of the neck and head but he was too fast for me to really get educated about it.
Luckily, my son and DIL, know how to give IV shots. If we ever have to do it, I plan on having them show me. I hate to just practice:)
Becky