Some people who get into police work, particularly those in urban settings, are deathly afraid of dogs. They tend to equate all dogs as in the same vein as those urban land shark pit bulls.
If an enterprising person wanted to make a zillion dollars they would design a device that officers, mailmen, UPS guys, etc, could put on their belts, and turn on when approached by dogs. This device would emit a ultrasonic “NO!!!” that would keep the animals at bay.
The point isn’t the officer’s fear of dogs, it is inuring the officer to the shooting of living beings, preferably fairly large bodied beings. After a time when it is humans that get shot on routine calls the people will begin to feel Terror which is what it is all about.