Found this recently on the net, very interesting info.
At the 2003 Tufts' Canine and Feline Breeding and Genetics Conference, Dr.Jerold S. Bell, DVM (Tufts University School of Veterinary Medicine) presented the results of a survey on GDV. It was done by Dr. Larry Glickman, an epidemiologist at the Purdue University School of Veterinary Medicine. Dr. Glickman conducted a controlled study on canine bloat, beginning in 1994. He followed 1,914 dogs from 11 different breeds who did not have a prior history of bloat. The findings are summarized below:
1. Breed with highest incidence= Great Dane. Breeds at higher-than average risk include the Bloodhound, Irish Wolfhound, Irish Setter, Akita, standard Poodle, German Shepherd Dog, and Boxer. All other deep-chested breeds and deep-chested mixed-breed dogs are also at higher risk than other dogs.
Several risk factors were identified.
1. Dogs with deep narrow chests have the greatest risk of developing bloat. An individual's risk can be estimated by measuring the depth and the width of the chest. Next, the number for the depth is divided by the number for the width. the idea is that the depth-to-width ratio represents the amount of room there is the stomach to move behind the ribcage. The higher the ratio, the more room there is for movement. So those dogs will have a greater risk of developing bloat.
2. Lean dogs were found to be at higher risk than fat dogs. Fat takes up space in the abdomen. So less fat creates more room for the stomach to dilate and flip. This does not mean that dog owners should let their dogs get fat. Obesity is still a bigger danger to a dog than bloat.
3. The risk higher for older dogs. Older large breed dogs over the age of 5 have a 20% higher risk of developing bloat. For giant breeds, the risk factor increases by 20 percent each year after the age of 3.
4. Genetics play a role. Immediate relatives of dogs that have had bloat have a 63 percent greater risk of developing the disorder.
5. Dogs that eat quickly have a 15 percent higher risk of developing bloat. This may be related to increased swallowing of air.
6. One popular preventative has been to raise the height of food and water bowls. Unfortunately in this study the practice was found to INCREASE the risk (by 110 percent!!).
7. Fearful, nervous, or aggressive dogs had a much higher incidence of bloat. Stress can also be an inciting cause since many dogs bloat after kenneling, or long car rides.
8. A slightly higher percentage of males than females developed bloat.
9. Several diet-related factors can be associated with an increased risk for bloat. Feeding only dry food, and/or feeding a single large daily meal are risk factors. Feeding one big meal dilates the stomach and stretches the hepatogastric ligament. This ligament helps maintain the stomach in it's normal position. Stretching of the ligament has been confirmed repeated in cases of bloat. It is also thought to be a reason why older dogs bloat. They have had a longer time to stretch that ligament repeatedly.
Dogs eating dry foods containing high fat content had a 170 percent higher risk for developing bloat. Lastly, dogs eating dry foods with citric acid and that were moistened prior to feeding had a 320 percent higher risk .
By contrast, feeding a dry food containing a rendered meat-and-bone meal decreased risk by 53 percent. Mixing canned food into dry food also significantly decreased the risk of bloat.
The study also disproved many popular theories regarding bloat.
1. There was no relationship between risk of bloat and exercise before or after eating. Most dogs bloated in the middle of the night with an empty, gas-filled stomach.
2.There was also no relationship found to vaccinations, to the brand of dog food consumed, or to the timing or volume of water intake before or after eating.
The report concluded with this statement:
"From the research performed to date, we can list several factors that, added together, can characterize the typical dog that develops bloat: a deep and narrow chest; leanness; a relative that has had a bloat episode; eating quickly; a dry-food diet; a single, large daily meal; stress; and a fearful, nervous, or aggressive temperament."
(Risk Factors for Canine Bloat Tufts' Canine and Feline Breeding and Genetics Conference, 2003 Jerold S. Bell, DVM Tufts University School of Veterinary Medicine)