Bloat in Dogs (GDV): An Overview
Dog Breeds
Gastric Dilatation and Volvulus (GDV), also termed Bloat or stomach torsion, is a medical condition in which the dog's stomach becomes overstretched by excessive gas, combined with the stomach twisting into an irregular position. Bloat is a life threatening condition that can result in death and requires immediate medical treatment.
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Definition of Bloat
Gastric dilatation and volvulus (GDV), commonly called “bloat” or “torsion,” is an extremely serious medical condition where a dog’s stomach becomes filled with gas that cannot escape. The stomach also can rotate around its short axis, often carrying the spleen along for the dangerous ride. By itself, “bloat” technically refers only to the gaseous distension of the stomach, without the flipping-over, or “torsion,” part of the condition. However, most owners think of “bloat” as referring to the syndrome of both gastric distension and rotation, and we will call both conditions “bloat” in these articles. Think of it as if the stomach is a balloon that keeps filling with gas, but the “escape route” is twisted or tied off. Eventually, the balloon will rupture. Similarly, the stomachs of dogs suffering from gastric dilatation and volvulus can rupture, spilling intestinal contents into the abdominal cavity. Bloat is life-threatening and requires immediate and aggressive medical attention if the dog is to survive. Without emergency treatment, bloat can be fatal within a matter of hours of the appearance of clinical signs.
Causes of Canine Bloat
The precise triggers of GDV are not well-understood. However, the physiological processes are. When the stomach rotates on its axis (think of this as the connection between the stomach and the esophagus on one end, and the stomach and small intestine on the other), gas in the stomach becomes trapped. It can no longer escape back up the esophagus through burping (called eructation), nor can it escape down through the gastrointestinal tract, because both the entrance to and exit from the stomach are twisted and thus obstructed. The increasingly distended stomach compresses the diaphragm and the major abdominal blood veins, shutting down digestion and reducing venous blood return to the heart. This, in turn, decreases the amount of blood that the heart can pump out into circulation, which causes an inadequate supply of oxygen to be distributed throughout the dog’s body. Vital organs become unable to function, the gastrointestinal tissues start to ulcerate and die (necrose), and within a very short period of time the dog goes into hypovolemic (low circulating blood volume) and hypotensive (low blood pressure) shock. The dog is now fighting for its life. Why this process happens is still a medical mystery. A number of different contributing factors have been suggested, but none have been proven.
Preventing Bloat in Dogs
Once a dog has bloated, it is more likely to bloat again. Surgical options are available to reduce the chance of bloating even before it has happened, as well as to prevent recurrence. The general name for this surgical procedure is gastropexy. When done preventatively, it is called prophylactic gastropexy. Another general term for the procedure is “stomach tacking.” There are several different ways that veterinarians can surgically attach, or “tack,” the stomach to the abdominal wall in an attempt to prevent it from torsing in the future. While these procedures are usually very helpful, they are not fail-proof. Other preventative measures involve dietary and exercise management and moderation. Many breeders and veterinarians recommend feeding at-risk dogs from elevated feeders, while some advise against this practice. Other suggestions are to restrict activity for an hour or so both before and after meals, and to feed at least twice daily. Dogs that eat a single, large meal of dry kibble and then drink large amounts of water and/or become active seem predisposed to bloat. Dogs with a history of bloat should be taken out of any breeding program.
Special Notes
Bloat is a life-threatening condition. Without immediate medical care, the chance of survival is extremely low. If you own a large deep-chested dog – or indeed any dog -- please make sure that you have a good relationship with your local veterinarian and that you are familiar with the signs of this condition, so that if it happens to one of your dogs, you are prepared to deal with it immediately.
Causes and Prevention of Bloat