Reverse coughing in a young dog - why does he do that?

Hearing a reverse cough for the first time is initially confusing. Humans don't experience this – it really does sound like the dog is coughing "inside itself." This is especially common in puppies and young dogs. For first-time dog owners, it can be quite frightening: Is the dog choking?

Here you can find out what reverse coughing is , how dangerous I think it is, and why the dog does it: