What Is Bloat in Dogs and How Can You Prevent It?
Large, Deep-Chested Dogs Are Most at Risk
You and I call it bloat, but to veterinarians it’s gastric dilatation-volvulus (GDV). There are other terms associated with the condition: torsion, gastric torsion, gastric dilation, but they all mean the same thing . . . extreme danger for the dog in its grip.
Bloat occurs when the stomach fills with air (dilatation), rotates on itself (torsion), and (in volvulus) cuts off its own blood supply, in effect causing the stomach to die.
Dilatation doesn't automatically mean volvulus will occur, but if it does, 35% of dogs that get to that level die.
OK, let’s go back and do this in slow motion. The stomach, at the top, is connected to the esophagus (the tube leading from the back of the throat to the stomach.
At the bottom, it’s connected to the duodenum (the section of the small intestine through which food exits the stomach).
In bloat, the stomach fills with air and begins to twist. This causes the esophagus and duodenum to crimp (this is what vets call torsion), much like when you turn a balloon into two sections by twisting it in the middle.
Once the stomach completely twists (what the vets call volvulus) it cuts off its own blood flow, increasing the swelling (like when the lab tech applies a tourniquet to draw blood).
The stomach is now a sealed bag that continues to inflate with gas and digestive juices. As the stomach distends, it presses against other organs, causing contact damage and compression that cuts off the blood supply to those other organs. Total elapsed time: probably less than three hours.
The Top 10 Dogs at Risk
Statistically, large, deep-chested dogs are more susceptible to the condition. The Top-10 breeds at risk, according to a Purdue University study, are as follows:
- Great Dane
- St. Bernard
- Irish Setter
- Gordon Setter
- Standard Poodle
- Basset Hound
- Doberman Pinscher
- Old English Sheep Dog
- German Shorthaired Pointer
Interestingly enough, German Shepherds are 12th, Boxers are 16th, Labs are 18th, Goldens are 22nd, and Rotties are 23rd. This order is based on risk compared to that of a mixed breed. The Miniature Poodle is the only breed with a lower risk factor than the mixed breed.
Various studies have produced a variety of factors that appear consistently, though not all inclusively, in episodes of bloat: male, deep-chested, underweight, fearful or high-strung, dry food, fed once a day, consumed rapidly, followed by lots of water, followed by heavy activity.
The Purdue study reported some interesting new factors they found consistent with bloat, such as food with fat among the first four ingredients, dry food containing citric acid that was moistened by the owner, having a raised food bowl, and having an immediate relative with GDV.
Remember when a raised food bowl used to be recommended to help prevent bloat? I guess they finally figured out that a raised food bowl extends rather than flexes the esophagus, allowing for the even faster consumption of food.
Shock May Occur
Shock is the major life-threatening abnormality in bloat, and it results when volvulus occurs and two major veins are compressed due to the expansion and rotation of the stomach. Organs and tissue die when the blood supply is cut off.
A dog that is going into GDV will wretch, try unsuccessfully to vomit, and perhaps appear restless, anxious, and to be having difficulty breathing.
The stomach will be distended, he may drool profusely, and ultimately may collapse. At this stage, surgery is probably the only option.
Immediate veterinary intervention begins with the vet working to stabilize the dog's cardiovascular system.
After that, the vet may insert a gastric tube or a needle into the stomach in an attempt to decompress the organ.
They may go right into X-ray to see if volvulus has occurred, and if so, prepare the dog for surgery. In surgery they'll rotate the stomach to its normal position and sew the stomach to the abdominal wall to prevent it from twisting again in the future.
Time Is of the Essence
The experts can't say exactly what causes bloat, but the factors listed above appear consistently enough to be suspected as causative.
If you're aware of these, you may be able to prevent an episode of bloat.
Even if your dog isn't high on the risk list, it's valuable for family members to be able to recognize the symptoms of bloat, and to be able to act quickly if they suspect it may be happening. In bloat, time is of the essence; you usually only have a few hours.
© 2012 Bob Bamberg