Dogs (n = 136) with gastric dilatation-volvulus (GDV) syndrome were followed over time to measure recurrence and mortality rates and to identify prognostic factors. Thirty-three (24.3%) died or were euthanized during the first seven days. Of 85 cases that were followed for up to three years, nine (10.6%) cases each had a recurrence of GDV and seven (8.2%) cases died or were euthanized. The median survival times for cases that had gastropexies and those that did not were 547 and 188 days, respectively. Depressed or comatose cases on admission were three and 36 times, respectively, more likely to die than alert cases, while cases with gastric necrosis were 11 times more likely to die.

A study was conducted of 101 dogs (i.e., case dogs) that had acute episodes of gastric dilatation-volvulus (GDV) and 101 dogs (i.e., control dogs) with nonGDV-related problems. The control dogs were matched individually to case dogs by breed or size, and age. Predisposing factors that significantly (p less than 0.10) increased a dog's risk of GDV were male gender, being underweight, eating one meal daily, eating rapidly, and a fearful temperament. Predisposing factors that decreased the risk of GDV significantly were a "happy" temperament and inclusion of table foods in a usual diet consisting primarily of dry dog food. The only factor that appeared to precipitate an acute episode of GDV was stress.

Body measurements, history of gastric dilatation-volvulus (GDV), and other data were obtained for 155 Irish setters at the 1994 National Specialty Show. The dogs ranged in age from 6.5 months to 12.4 years (mean+/-standard deviation [SD], 3.6+/-2.6 years); 11 (7%) of the dogs had histories of GDV. Gastric dilatation-volvulus risk increased 33% for each year of age (p of 0.01). Dogs with the deepest thorax relative to width (ratio range, 1.61 to 1.85) had a significantly greater GDV risk than those with the shallowest thorax (ratio range, 1.20 to 1.50); the odds ratio was 8.45; the 95% confidence limits were 1.44 to 49.57; and the p value equaled 0.02. Having a relative (particularly a parent) with GDV also increased GDV risk. Five-generation pedigrees yielded a significantly higher mean coefficient of relationship for the 11 dogs with GDV than for the 11 dogs without GDV.

Thoracic depth/width ratios (TDWRs) were calculated from measurements of the parents (i.e., common dam and two sires) and puppies in two litters of Irish setters. The TDWRs of the parents, distribution of TDWRs in the litters, and comparisons with earlier population studies suggest that an incompletely dominant major gene and a background of minor genes and environmental factors are responsible for the TDWR. A history of gastric dilatation-volvulus (GDV) (i.e., bloat) was correlated with high TDWRs in this family as it was for Irish setters and certain other breeds studied earlier. It may be possible to reduce the incidence of GDV by selective breeding of dogs with lower TDWRs.