Sub Q - Subcutaneously (sub) meaning under; (cutaneously)of, relating to, or affecting the skin
Ex: Submarine (sub) under; (marine) water
This is interesting. I give the shots by pinching the skin of both cattle and dogs. When the skin is up and away from the muscle, I know and it ensures, that I am not going into the muscle. I have never had any problems but you have to be aware of what you are doing. As with anything.
If you are pulling an inch of skin away from the animal an you just stuck a two inch needle in...... Uh..... you are going to hit muscle or come out the back side. Its not rocket science.
Point the needle directly towards the ground - holding it like you are about to stab something with a knife in your fist - run your hand out and into the side of the animals neck and stab downward - almost parallel to the neck surface. Needle goes in under the skin and does not enter the meat. Ram the vaccine home with your thumb - unless you are using a gun which I doubt. That's another story.
I am not seeing what makes this method so much bettter. If you put a little too much angle, with a good sharp needle you can easily hit the muscle. The only thing that makes is safer is because you are only using one hand so you are less likely to stab the other hand. But you have to be more accurate with the needle because the target zone between the skin and muscle is smaller.
I have seen it done both ways. No doubt that both methods will work and you can do both fast when you have done enough of them... but unless I am missing something... one is no better than the other.