The dog has a dental cavity bitten by a big dog. You need to check whether the wound is serious. If it is not serious and there is no bleeding, you need to clean the hair around the wound first, then rinse the wound with saline, and then apply iodine. Disinfect and finally bandage the wound; if the wound is deep, it is best to take the dog to the pet hospital for examination and injection of rabies vaccine to avoid rabies infection after cleaning the wound.