If you even suspect that your dog may suffer from bloat, time is of the essence, THIS IS A MEDICAL EMERGENCY THAT REQUIRES IMMEDIATE VET ATTENTION!
If you own a breed that is susceptible to bloat (Great Dane, St. Bernard, Weimaraner, for example), then learn the signs of bloat now, and learn what you can do to help prevent it.
Studies can't say for sure what really causes bloat, they have just been able to identify breeds and types of dogs that are more susceptible to it, ways to lessen the chances of getting it, and have dispelled some of the rumor and myth about it.
The following links are all encompassing in what bloat is, how to lessen the chances, dispelling myths (you may have read that raised bowls decrease the risk of bloat, but that is not true: raised bowls actually INCREASE the risk of bloat), and educate in how important it is to act fast if you suspect that your dog has bloat.
Learn about bloat now... it may help you save the life of your dog if it strikes:
Video of a dog suffering from bloat (the dog is fine now)
Extract of the Bloat (GDV) Study