By Dr. Becker
Recently, the American Kennel Club's Canine Health Foundation put out a call to researchers interested in receiving $250,000 in funding to study gastrointestinal physiology, and specifically, the fatal condition known as bloat, or gastric dilatation volvulus (GDV) in dogs.
The Foundation is also making training available to veterinarians on surgical techniques used to prevent bloat that can be accomplished when a dog is undergoing a spay or neuter procedure.
According to Dr. Shila Nordone, chief scientific officer of the Foundation:
"Bloat is devastating for dog owners when it occurs. Through this major funding effort, researchers, for the first time, will have the resources they need to work towards establishing the causes and pre-dispositions for bloat. Once we understand why bloat occurs, we will have better treatment options and possibly be able to prevent the syndrome from occurring in the first place."
In addition to the research grants and continuing education for vets on surgery to help prevent bloat, the Canine Health Foundation scheduled a free webinar in mid-2013 for dog owners who want to learn about the possible causes of bloat, what breeds are most susceptible, bloat symptoms, and medical treatment of the condition. (You can visit this page to get more information on the webinar.)
What Exactly Is 'Bloat' in a Dog?
If your pet has bloat, or gastric dilatation, it means the stomach has filled up with gas and air but remains in position. Gastric dilatation volvulus is when the bloated stomach then twists around on itself, squeezing off the blood supply and creating the potential for significant damage to other internal organs. GDV is a life-threatening event in dogs. Tragically, 30 percent of the time it proves fatal.
That's why it's important for dog owners to know which breeds are at highest risk for the disorder and the symptoms to look for. It's vitally important that dogs suspicious for GDV be seen by a veterinarian immediately.
Symptoms of GDV Are Hard to Miss
These include a belly that has suddenly grown very large with air; belching, retching or vomiting that is mostly unproductive as your dog tries to get rid of the gas and air in her stomach; abdominal pain that makes it very difficult for her to move around; restlessness that is quickly followed by a rapid decline in the dog's condition; and shallow, rapid breathing, and pale gums.
If your dog has simple bloat without the twisting action, he should be able to relieve the pressure by belching. But with full GDV, there's no way to expel the gas and air from the stomach because both the entry and exit are pinched off by the torsion (twisting).
Since the spleen is attached to the stomach, when the stomach twists on itself, it also cuts off the blood supply to the spleen and splenic vessels. When abdominal vessels are pinched off, no blood can flow to other organs in the area and the blood flow back to the heart is also compromised. This can put your dog in a state of shock, and it can all happen very quickly -- in as little as 20 minutes to an hour after the volvulus develops.
Chances are you won't be able to tell whether your pet is experiencing simple bloat or bloating with volvulus, so you still need to get to your vet's office or an emergency animal hospital right away. The only way to know for sure what is happening is with an x-ray, and since GDV is associated with a high mortality rate, you want to err on the side of caution and have your dog seen immediately.
Without urgent veterinary care, the stomach will ultimately rupture and cause peritonitis, a fatal abdominal infection.
Risk Factors to Be Aware Of
There seems to be as many opinions on risk factors for gastric dilatation volvulus as there are researchers studying the condition and vets treating it. The fact is we just don't know at this time all the causes of the disorder. So it's important to understand that you can do everything in your power to try to prevent the problem, and your dog may still develop GDV.
- Large and giant breed dogs with deep, narrow chests seem at highest risk for bloat and GDV. The breeds most commonly diagnosed include the Great Dane, Basset Hound, Saint Bernard, Doberman Pinscher, Weimaraner, Old English Sheepdog, Irish Setter, German Shorthaired Pointer, Gordon Setter, Newfoundland, Standard Poodle, and German Shepherd.
- Other dogs at increased risk include those who are underweight and older animals. Dogs with a happy personality may have less risk.
- An older study of GDV done at Purdue University School of Veterinary Medicine suggested that elevated food dishes increase a dog's risk, and then there are those who believe elevated dishes help to prevent the problem. In my opinion, it's not so much about the dog's bowl as how fast he eats. Dogs that seem to inhale their food and swallow plenty of air in the process are in my experience at higher risk for GDV.
- Other dietary habits considered to be risk factors for GDV include eating large amounts at each meal, eating just once a day, exercising shortly after a meal, drinking large quantities of water right after eating, and being in a stressful situation right after eating.
- A study by veterinary faculty at the University of Pennsylvania published last year in the Journal of the American Veterinary Medical Association1 points to dry kibble as a significant factor associated with increased risk of GDV. This makes all kinds of sense, since the majority of commercial dry dog food is loaded with grain-based carbohydrates that are highly fermentable. Fermentation, of course, produces gas. My recommendation, as always, is to feed a balanced, species-appropriate diet, which will reduce fermentation of food in the stomach and the risk of gas buildup and bloat.
- A retrospective case-control study2 conducted in the U.K. and published last year concluded that gastric foreign bodies are a significant risk factor for GDV. A gastric foreign body is defined as "nondigestible or slowly digestible material palpated during gastrointestinal tract examination that was causing clinical signs or was > 10 cm in length or > 2 cm in width."
- Other suspected risk factors include increased gastrin concentration (gastrin is a hormone that controls release of acid in the stomach); decreased stomach motility and delayed gastric emptying (meaning food stays in the stomach longer than normal); and removal of the spleen.
- In terms of recovering from gastric dilatation volvulus, according to a retrospective study3 published in 2010 involving over 300 dogs who underwent surgery for the condition, the factor that proved to be the most significant in decreasing the overall mortality rate was time from presentation to surgery. This is why I can't stress enough the importance of getting your dog immediate veterinary care if you suspect bloat or GDV.
Things You Can Do to Help Prevent GDV in a High-Risk Dog
Feed a species-appropriate diet with no grains or other fermentable carbohydrates, and feed two to three smaller meals a day vs. one large meal.
Don't exercise your dog for an hour after he eats, and also withhold large amounts of drinking water during that time.
If your dog eats too fast, try spreading the food out on a cooking sheet, or use a bowl designed to slow down eating.
Be very careful not to allow your dog to have bones, dental chews, toys, or other foreign objects that are difficult or impossible to digest.
Minimize stress on your pet. Make sure she is well exercised (though not right after meals, as I've discussed). Most large breed dogs need lots of daily physical activity to maintain muscle tone and range of motion, decrease cortisol levels, and relieve boredom. You'll also want to keep vaccines to a minimum to reduce immunologic stress, and keep a lid on the amount of chemicals your pet is exposed to orally, topically, and in the environment.
A surgical procedure some vets offer for high-risk GDV dogs is called gastropexy, and it is typically performed at the same time the pet is spayed or neutered. Gastropexy tacks the stomach to the body wall so that it cannot move and twist around on itself in the event the dog becomes bloated. My first recommendation would be to try to prevent GDV with the right diet and other lifestyle choices. However, if your dog is a breed prone to the disorder and eats a primarily dry food diet, gastropexy may be your best option.