You stay away from any injection.
This last time I used a dog, I hired a Chihuahua. Literally, I hired a Chihuahua to make noise as a bodyguard, yes. Cause I figured big dog. You can get them, they smell the meat far away, raw meat and you can feed 'em and they're dead if anybody wanted to get to me.
So, your Chihuahua is gonna bark at this faint sound of anything moving.