Introduction
“Bloat” in dogs is a term commonly used to refer to a medical condition called Gastric Dilatation and Volvulus, or “GDV.” Other common names for GDV include “stomach torsion,” “spleen torsion,” “torsion” or “twisted stomach.” GDV is an extremely serious medical condition and must be considered to be a life-threatening emergency when it happens. It is extremely painful and is a true emergency. A dog with a bloated and twisted stomach will die in great pain in a matter of a few hours, unless immediate and drastic intervention is taken.
Causes of Bloat
There are two basic components of Gastric Dilatation and Volvulus. The first part is the “dilatation,” which essentially is the “bloating.” The second part is the “volvulus,” or the torsion or turning of the stomach and/or spleen.
Bloat occurs for many reasons probably in some sort of combination, but the exact cause is still unknown. Basically, the dog's stomach fills up with air (“dilates”) and therefore puts an abnormal amount of pressure on other abdominal organs, including the diaphragm. This is probably tied to some dysfunction of the sphincter between the esophagus and the stomach, combined with an obstruction of the outflow valve of the stomach into the intestines through what is called the pylorus.
It also appears that dilatation occurs as a result of excess swallowing of air. Most mammals do swallow air (including people), but most of us burp (“eructate”) to clear the excess air/gas from our stomachs. For some reason, dogs that bloat do not release this swallowed air normally. As a result, the stomach puffs up and the increased pressure on the diaphragm makes it hard for the dog to breathe.
Because of its size, the air/gas-filled stomach also compresses blood vessels in the abdomen, which decreases the amount of blood flow back to the heart and also effectively shuts down digestion. When the stomach is gas-filled, it more easily flips over (“torses” or “tortions”). When the stomach rotates, it further cuts off blood supply to vital organs and to the heart. In turn, the stomach and entire gastrointestinal tract start to die from lack of blood supply and proper oxygenation, and death is imminent. While the dilatation of the stomach does not always lead to volvulus (torsion, or flipping) of the stomach or spleen, when torsion does occur it almost always happens in association with bloating.
Factors attributed to developing bloat
- Older age: dogs over 7 years of age are more likely to develop GDV
- Possible genetic predisposition
- Breed predisposition: Large breeds with deep and narrow chests (Great Dane, Saint Bernard, Weimaraner, Irish Setter, Gordon Setter, Standard Poodle, Basset Hound, Doberman Pinscher, Old English Sheepdog, German Shorthaired Pointer, Newfoundland, German Shepherd, etc.).
- Gender: Male dogs seem to be twice as likely to develop GDV as do females, and neutering/spaying does not seem to reduce the likelihood of bloat/torsion.
- Stress: Dogs that tend by temperament to be nervous or fearful, and dogs who are subjected to especially stressful situations, seem to be more likely to bloat.
- Eating habits: dogs that are fed only once a day are more likely to suffer from bloat than are those fed 2 or 3 times a day. Also, dogs who eat really rapidly, or who exercise right after a meal, tend to be at increased risk for GDV.
Studies have indicated that the risk of bloat in dogs perceived as happy by their owners is decreased, and increased in dogs perceived as fearful. This may be due to the physiological effects of the dog's personality on the function and motility of the gastrointestinal system. Dogs with inflammatory bowel disease may also be at an increased risk for bloat.
Preventing Recurrences of Bloat
Once a dog has suffered bloat and/or full GDV (including torsion of the stomach and/or spleen), recurrence is more likely and occurs in up to 80 percent of dogs treated by non-surgical means only.
To prevent recurrence, a gastropexy is often performed at the same time the GDV is treated surgically. This procedure (also called a “stomach tack”) involves major abdominal surgery to attach the stomach wall to the body wall and is designed to prevent the stomach from twisting inside the abdominal cavity in the future. While dogs that have had gastropexies may still develop gas distension of the stomach, there is a significant reduction in recurrence of gastric volvulus, or the more serious twisting of the stomach and spleen. One study showed that out of 136 dogs that had surgery for bloat, only 4.3 percent of those that did have gastropexies had a recurrence, while 54.5 percent of those without the additional surgery recurred.
Gastropexies can also be performed as a preventative measure (prophylactically) in dogs considered to be at high risk of bloat, including dogs with previous episodes of bloat or with gastrointestinal diseases that often lead to bloat.
Other preventative measures include:
- Feed your dog at least two times daily, with multiple small meals rather than one large one
- Keep fresh water available for your dog at all times
- Prevent vigorous exercise or other excitement or stressful activities around mealtime
- Make diet changes gradually
- Feed susceptible dogs in a quiet, private location
- Some people suggest feeding susceptible dogs with raised feeders; others prefer feeding at ground level. Discuss this with your breeder and veterinarian.
GDV is a life-threatening condition that occurs most commonly in our large, deep-chested breeds. If you own one of these beloved dogs, please make sure that you have a good relationship with a local veterinarian and that you are familiar with the clinical signs of “bloat” so that if it happens to one of your dogs, you can deal with it immediately.