The sudden enlargement of a dog’s belly may be caused by obesity, ascites, liver disease, etc. You should pay attention to the dog’s diet management, feed small and frequent meals, and take the dog to exercise appropriately to promote physical health. If it is caused by disease, , then you need to take the dog to the pet hospital for examination and treatment. During this period, the dog will be given nutritional supplements, and do not blindly use drugs to avoid life danger.