gastric dilatation volvulus, or gastric torsion and bloat, primarily affects breeds with deep, narrow chests, such as great danes, st. bernards, german shepherds, standard poodles and irish setters. the stomach twists on its supporting ligaments, sealing off the exits, and the contents begin to generate gas pressure which is very painful and rapidly causes shock and necrosis of large areas of stomach tissue. it can be fatal within a few hours. dogs who have experienced bloat are very susceptible to recurrences. treatment involves stabilization and abdominal surgery to tack the dog's stomach down to prevent recurrence (gastropexy).