A dog with one ear crooked and then shaking its head wildly may be caused by water in the ear, ear mites, parasite infection, etc. It is best to check whether there are ear mites or parasites in the dog's ears. If so, you can use pet-specific ear cleaning solution to clean the dog's ears. If the dog often shakes its head for no reason, it is best to take the dog to the pet hospital for examination to avoid delaying the condition.