It won’t be this year, and most likely not next, but sometime in the next few years, we may actually find out – once and for all – what causes gastric dilatation-volvulus, more commonly known as bloat, and what triggers its occurrence.
The American Kennel Club Canine Health Foundation offers this description of GDV: “Gastric dilatation-volvulus, or bloat, is a devastating condition that can develop in any dog, although it is particularly common in large-breed and deep-chested dogs. Bloat develops when the stomach fills with air and then twists on itself, preventing air and liquid from leaving the stomach. Over time, the stomach gets larger and larger. This cuts off circulation and prevents blood from getting back to the heart from the rest of the abdomen and the rear legs. The stomach wall itself can also be severely damaged from loss of blood flow as can the spleen. Bloat requires immediate stabilization and prompt surgical correction, and may still be fatal in some severely affected dogs.”
To dig into the actual cause of GDV, the Canine Health Foundation has secured $250,000 for the first of up to three similar funding cycles for research grants, as part of its Bloat Initiative, as well as more than $50,000 toward the second round of funding.
The number of dogs diagnosed with GDV each year in the United States is “really unknown,” according to Elizabeth Rozanski, D.V.M., an associate professor of emergency and critical care at the Tufts University Cummings School of Veterinary Medicine in North Grafton, Mass. “The best estimates would be in the 50,000 range,” she says. Fewer than 5 percent survive without surgery, she says, and those are dogs whose stomachs return to their “normal position spontaneously. This is very uncommon,” she adds.
Of the last 500 dogs treated at Tufts, Rozanski says about 80 percent had surgery to untwist the stomach, then tack it to the abdominal wall to help prevent future occurrences. Of those having surgery, about 15 percent don’t survive because of “completely necrotic stomachs” or post-operative “multiple organ failure.”
If national statistics echo those at Tufts, and based on Rozanki’s estimate of nationwide GDV occurrence, about 7,500 dogs die each year – and those are just the ones diagnosed and treated. Some owners simply find a dog dead in its kennel or elsewhere if the dog’s reaction to GDV goes unnoticed during the night, for example. And some dogs are euthanized at veterinary clinics upon diagnosis “for sure,” she says.
“I wish we had real numbers,” Rozanski adds.
Shila Nordone, Ph.D., chief scientific officer for CHF since January 2012, says there have been “several very strong epidemiological” research efforts, and “people have looked at feeding practices and several different things.” Indeed, a survey of 2,500 dogs, whose results were published in the June, 15, 2012, issue of the Journal of the American Veterinary Medical Association, concluded: “In dogs with a high risk of GDV, regular moderate daily and postprandial [after a meal] activity appeared to be beneficial. Feeding only commercial dry dog food may not be the best choice for dogs at risk; however, supplements with fish or eggs may reduce this risk. The effect of neuter status on GDV risk requires further characterization.” No definites there.
“At the end of these, there are only associations,” Nordone says. In other words, walking after meals is associated with GDV prevention, but it’s not guaranteed. Adding fish or eggs to commercial food “may” help. As to whether neutering has any effect: Who knows? We’ve heard that dogs shouldn’t eat out of raised dishes, we shouldn’t add water to kibble and myriad other things that might increase the risk of bloat.
Some of the breeds considered at high risk for GDV are German Shepherd Dogs, Great Danes, Collies, Gordon Setters, Irish Setters, Bloodhounds, Akitas, Saint Bernards, Mastiffs, Standard Poodles, Labrador Retrievers, Golden Retrievers, Doberman Pinschers and Chow Chows, according to various studies.
The real problem is “We don’t know what gets it started,” Nordone says, “what makes it turn into GDV. There have been few research efforts that have tried to define the mechanism underlying bloat.”
One common association with bloat is stress. This can be due to a “stressful event, such as boarding,” or just the fact that a particular dog is more nervous than the average dog, Nordone says. “That’s one of our special topics of interest – the elucidation of the neural pathology of GDV and improved understanding of how psycho-stressors” may play a role. “There’s a lot of interplay between the nervous system and the gastrointestinal system,” she says.
The request for research proposals details some topics of interest to the Bloat Initiative, such as “genetic risk variants,” explanations of “pathophysiological mechanisms,” “characterization of pathways mediating gastrointestinal motility [spontaneous movement] changes associated with GDV,” and explanations of “the neural pathology of GDV and improved understanding of how psychosocial stressors precipitate GDV” and of “whether environmental factors anecdotally associated with bloat [such as heat and humidity] are associated with aberrant physiological responses in high risk breeds.”
Researchers who have “hypotheses as to why some dogs bloat and others don’t,” as well as those who would take a genome-wide look at the canine for answers are expected to apply for grants, according to Nordone. What leads to GDV is “not going to be a single [gene] mutation,” she says.
Nordone says the committee deciding who will get research grants will take particular interest in proposals that include collaborative efforts. Neurologists, gastroenterologists and microbiologists are some of the research professionals who can “pool their expertise to help solve the problem. When you get people together with a broad range of experience, you really get synergy,” she says.
The foundation has “cast a wide net,” she says, to “see what comes of it.
“Hopefully if we can start to understand the mechanism of how and when bloat starts, we can start treating it before it gets into torsion,” the twisting that keeps air and fluid from leaving the stomach.
Regarding the first commitments for $250,000 worth of research and education, Nordone says, “It’s enough to get it started. For veterinary medicine, $250,000 awards are large. We’re hoping to make at least two to three $250,000 awards. In two to three years, we’ll have a much better idea of at least some of the mechanisms underlying GDV.”
Even over the telephone, Nordone’s feelings for this project come through loud and clear. “I’m excited because I think we can really put some evidence under why we see stress or gut motility associated with bloat. I’m excited about our donor excitement. The breed clubs and individual owners are very enthusiastic about us trying to do something about this. I think it’s going to be great.”
Donating toward the Bloat Initiative thus far are the Collie Health Foundation, Greyhound Club of America and the Irish Setter Club of America Foundation at $50,000-plus each; the Basset Hound Club of America and German Shepherd Dog Club of America at $25,000 to $24,999; the American Black & Tan Coonhound Club, American German Shepherd Dog Charitable Foundation, Briard Club of America Health and Education Trust, Gordon Setter Club of America, Greater Swiss Mountain Dog Club of America and Weimaraner Club of America at $10,000 to $24,999; and the American Bloodhound Club, English Springer Spaniel Field Trial Association, English Springer Spaniel Field Trial Association Foundation, Flat-Coated Retriever Foundation, Kuvasz Fanciers of America, TarTan Gordon Setter Club and Versatility in Poodles at $2,500 to $9,999.
Another part of the CHF Bloat Initiative is education for dog owners and veterinarians. Rozanski will give a webinar for owners in mid-2013. (We’ll be sure to let our readers know when the webinar is posted on the CHF website.) The webinar will include what’s already known about possible causes, susceptible breeds, symptoms, medical intervention and an explanation of research needed. “Because bloat progresses so rapidly, part of our focus is on educating the public on the signs and symptoms to look for if they suspect their dog may have bloat,” Nordone says. The foundation will also provide continuing education for veterinarians showing surgical procedures that can be used for prevention during spay and neuter surgeries.
Nordone says CHF “loves hearing from dog owners” and “getting feedback on what we’re doing and why we’re doing it.” She encourages Best In Show Daily readers to contact CHF and to go to the foundation’s Facebook page.
Grant awards are scheduled for announcement on October 1.