If a dog is involved in a fight or altercation at the park, owners should act quickly and calmly to separate the dogs without putting themselves at risk of injury. Use a loud noise, water spray, or a barrier like a blanket to distract and separate them if possible. Once separated, check the dog for injuries and consult a veterinarian if there are any wounds or signs of distress. It’s essential to also exchange contact information with the other dog owner and report the incident to park authorities if needed.