When you see a dog in public, do you rush over to tell him he is a very good boy? Maybe it’s your dog-crazy child who has spied a patch of fur and a wet nose and wants to dive in for a hug. There might be squeals and pleas of “can I pet him?” Dogs have that effect on a lot of us.

But many dog owners would like you to resist that urge. Chances are it’s ok to pet, but what if the dog is reactive and will misbehave? The handler on the other end of the leash might be working on those bad habits, and you’re not helping.