The bloodshot eyeballs of a dog may be caused by abdominal bleeding or intracranial hemorrhage. It is best to take the dog to the pet hospital for examination and treatment in time to avoid life-threatening injuries. It is best not to hit the dog hard, especially in some fragile and sensitive parts, such as the head, belly, hind legs, waist, etc. If the dog makes a mistake, you can scold the dog or spank the dog's butt muscles.