Called Bloat (at least here in the U.S.)... it can't bred out of larger breed dogs, but one can ameliorate its occurrence by simply waiting at least 30 minutes to an hour after they've been fed before any strenuous exercise. Especially if they've eaten a larger meal than usual. The phenomena can occur in any dog, but ismore common in deep chested dogs... German Shepherds, Labradors and, of course the giant breeds such as Great Danes.
If your dog suddenly, for no other apparent reason begans vomiting (even water) and bringing up only white frothy material... be suspicious of Bloat. A veterinanrian can often treat the condiition with only skilled manipulation of the dog's stomach, thereby avoiding surgery. But be aware that the condition is often fatal in less than 48 hours if untreated. We lost a medium sized Blue Heeler here on our ranch in the western U.S. before we became educated on the issue...