Causes of Canine Bloat
Gastric dilatation and volvulus (GDV or bloat), is a life-threatening medical condition in which the stomach becomes increasingly distended with gas to the point where it can rupture. What triggers bloat is not well understood. However, the physiological processes are. When the stomach rotates on its long axis (think of this as the connection between the stomach and esophagus on one end, and the stomach and small intestine on the other), gas and fluids become trapped. The spleen, which is attached to the stomach wall, also flips over. Normal production of gas in the stomach continues, but because both the entrance into and exit from the stomach are obstructed, gas can no longer escape up the esophagus through burping or vomiting, or down the gastrointestinal tract and out through the anus (flatus). As the stomach contents continue to ferment, the bloating stomach compresses the diaphragm and major abdominal blood vessels, shutting down digestion and reducing blood return to the heart. This decreases the amount of blood that leaves the heart, lowering blood pressure and causing poor distribution of oxygen throughout the dog’s body. Gastrointestinal tissues start to ulcerate and die, vital organs start to fail, and within a very short period of time the dog goes into hypovolemic and hypotensive shock from low circulating blood volume and low blood pressure. At this point, the dog is fighting for its life and will die without treatment.
A number of contributing factors have been suggested, although none of these have been proven to cause bloat. They include:
- Anatomical/genetic predisposition
- Deep, narrow chest
- Skittish, fearful temperament
- Poor nutrition
- Eating only one large daily meal of dry kibble
- Eating rapidly
- Exercising vigorously before or after eating
- Drinking lots of water after eating
Once a dog has bloated, it is more likely to bloat again. A surgical procedure called gastropexy or stomach tacking, is available to reduce the risk of bloat. When done preventatively, this is called prophylactic gastropexy. There are several different ways to surgically attach the stomach to the belly wall to hopefully prevent it from flipping over in the future. While stomach tacking usually works extremely well, it is not fail-proof. Other preventative measures include dietary and exercise management and moderation. Many authorities 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 become active may be predisposed to bloating.
Bloat is a life-threatening emergency. Without immediate intervention, the chance of survival is extremely low. Owners of any dog, but especially a large deep-chested dog, should be sure to establish a good relationship with a nearby veterinarian and become familiar with the signs of bloat, so that if it happens they are prepared to deal with it immediately.