This is how it resonates with me (it might be quite different for you).
The (black) dog is an event you have coming up, probably major.
It is running towards you. Running represents time.
To "shoot" is to prepare adequately for the event.
The machine gun fire is probably friendly support that is there to get you ready for the event.
If that fits, and there is 1-2 key people with whom it would be absolutely vital to clarify the event with and move on it, contact them and they will