The only bloat I ever saw was a Dane, and unfortunately the owners didn't know the warning signs, and by the time they got to us, he was already on his way to the Bridge. They said that he'd drank nearly a gallon of water all at once and then started acting weird after that, but thought he was just full.
I used to have a Dane, and I was always really careful not to let him eat too much at once, drink too much at once, and exercise right after a meal.
From what I've heard, the dogs that have to worry the most are the ones who have the deep chest with a little waist like Danes, Dobies, Boxers, Greyhounds, Poodles etc., but no dog is immune to it.