1. If you have a concealed carry permit, or live in a state where one is not required, keep your gun handy. Not all dog owners are good ones, and a 7 year old boy might want to keep his face.
I hear having a face is a good thing. Also, if you don't carry a gun, look into carrying a brick, apparently.
2. If you are the parent of small children, keep your eyes open. Bad things happen quickly.
I have two wonderful kids and I have had to ward off dogs plenty of times while walking in our neighborhood and in parks. Only once did I ever have to actually touch a dog in question; it tried to bite my daughter and my yelling at it and waving my arms wasn't scaring it away. Eventually I resorted to grabbing it by the scruff of its neck, and drop kicking it a few feet and it ran away. A nice .380 in my pocket would have left me with other options if the situation had gotten worse.
KEEP YOUR KIDS SAFE
Hat tip to A NC Gun Blog for the story.