Closeup of dog tugging on leash

Q: My dog has this weird habit of lunging at people’s feet when I walk him on the street — but he does it only once the person has passed. What is this all about?

A: I can imagine how stressful this situation must be for you, especially when you’re just trying to exchange friendly greetings with someone like a neighbor.

There are a few reasons your dog could be displaying this behavior.

Instinct: Canines with herding backgrounds are notorious for nipping at the heels of other dogs, sheep, horses and even people. Border Collies and Australian Shepherds, for example, are known for exhibiting ankle- and heel-nipping behavior, which can show up in puppyhood.

The behavior is usually brought on by fast movements or walking away from a dog with your back facing him.

Anxiety: Your dog may also feel frustration or anxiety when people pass him on the street, either because he wants that person to pet him or he feels anxious about the individual.

Entertainment: For some dogs, heel nipping may actually be a fun game.

Regardless of the reason for the behavior, your dog knows that when he lunges or nips at a person’s ankles, they move away from him, which either relieves emotional stress or becomes the exciting end to a game. If your dog exhibits anxiety or aggression when a person’s back is turned, it’s likely because the individual poses less of a threat to him in that position than facing him head on.

To combat this habit, give your dog an alternative behavior to perform and reward it. One of my favorites: Ask him to sit and stay when a person approaches. You may need to treat him multiple times when you first practice this technique as a person walks by, eventually working up to treating only after the individual has passed.

By giving your dog a default command, he’ll be less able to lunge and more likely to relax in these situations. If you use a head harness, you’ll also have greater control over your dog’s unruly ankle-attacking behavior.