Children run across the park path and your dog barks and pulls toward them. Whether your dog is afraid, excited by movement, or trying to chase, a child should not become part of a training experiment. Move away early, keep your dog on a secure lead, and choose a different route if you cannot provide a safe gap.
Don't ask children to approach with treats, stand still, or help your dog "get used to" them. If your dog has snapped, lunged close enough to reach someone, or you cannot safely hold the lead, seek a qualified, reward-based behavior professional for an individual safety plan. A veterinary check is important if the reaction is sudden or worsening.
Build distance before building skill
Practice a U-turn away from people in a calm place. Reward your dog for turning and moving with you. On walks, use it as soon as you see a busy play area. Choose routes with clear sightlines rather than narrow paths beside schools or playgrounds.
A professional may help you set up controlled practice at a distance where your dog can observe activity without stiffening, staring, or barking. It must not involve asking children to get close. Reward your dog for looking back at you, sniffing, or walking calmly away. If they cannot respond, the setup is too hard.
At home, children and dogs need active adult attention and a way to separate. Never leave a child alone with a dog who has shown discomfort, even if the dog seems relaxed in other moments. A good plan gives everyone room, rather than hoping the next encounter will be different. For more on planning child-and-dog boundaries, see the dog-and-child safety guide, keep your dog at a safe distance from children while you seek individual help
Sources: Dogs Trust: Dogs and children living happily together. Dogs Trust: Reactive dogs - why it happens and how to help.