Clean the injection site well with alcohol. Secure the animal so it does not move when you inject it and hurt itself. When you put the needle in draw back on the syringe- SLIGHTLY- to ENSURE YOU ARE NOT IN A VEIN. If you do NOT get blood in the syringe go ahead and inject slowly. If you get blood simply pull the needle out and inject again in a different spot. Follow the same procedure to ensure you are not in a vein.