When I was taught how to do injections, for intramuscular ones I was told to pull back on the plunger slightly once the needle was inserted to check for blood to make sure I wasn't in a vein (this is in the neck, following BQA). However, at work my boss just tells me to stick it and do it. I assume the risk of damaging or killing the animal changes depending on what you are injecting. What's your opinion? Just doing it is easiest of course, but is that putting the animal in any real danger?