Pets and People: Bloat is a Life-Threatening Emergency


Many injuries and physical disorders represent life-threatening emergencies, but there is only one condition so drastic that it overshadows them all in terms of rapidity of consequences and effort in emergency treatment: the gastric dilatation and volvulus, called commonly, “bloat.”

Normally, the stomach contains a small amount of gas, some mucus, and any food being digested.  It undergoes a normal rhythm of contraction, receiving food from the esophagus above, grinding the food, and moving the ground food out to the small intestine at its other end.  This proceeds uneventfully except for the occasional burp.

In the bloated stomach, gas and/or food stretches the stomach many times its normal size, causing tremendous abdominal pain.  This grossly distended stomach tends to rotate, thus twisting off not only its own blood supply but the only exit routes for the gas inside.  The spleen, which normally nestles along the greater curvature of the stomach, can twist as well, cutting off its circulation.  The distended stomach becomes so large that it compresses the large veins that run along the back returning the body's blood to the heart, creating circulatory shock.

Not only is this collection of disasters extremely painful, it is also rapidly life-threatening.

A dog with a bloated, twisted stomach (more scientifically called gastric dilatation and volvulus), will die in pain in a matter of hours unless drastic steps are taken.

Dogs weighing more than 99 pounds have an approximate 20 percent risk of bloat.  The risk of bloating increases with age.  This condition affects dog breeds which are said to be deep chested, meaning the length of their chest from backbone to sternum is relatively long while the chest width from right to left is narrow.  Examples of deep chested breeds would be the Great Dane, Greyhound, and the setter breeds. Still, any dog can bloat, even dachshunds and chihuahuas.

Classically, the bloated dog has recently had a large meal and exercised heavily shortly thereafter. Still, we usually do not know why a given dog bloats on an individual basis.  No specific diet or dietary ingredient has been proven to be associated with bloat. Some factors found to decrease the risk of bloat are listed below:

Adding table scraps, canned food, or non-kibble supplements to the dog's kibble diet reduced the risk of bloat in some studies.  More research is needed to fully understand the implications of this.

Feeding a dry food containing a calcium-rich meat meal (such as meat/lamb meal, fish meal, chicken by-product meal, meat meal, or bone meal) listed in the first four ingredients of the ingredient list.

Eating two or more meals per day.  Contrary to popular belief, cereal ingredients such as soy, wheat, or corn in the first four ingredients of the ingredient list do not increase the risk of bloat.

A bloated dog is distressed, makes multiple attempts to vomit, and the upper abdomen is hard and distended from the gas within.  In a well-muscled or overweight dog, the distention may not be obvious.  There are other potential emergencies (sudden abdominal bleeding from a ruptured tumor, for example) that might have a similar presentation so radiographs may be needed to determine what has happened.  The hallmark presentation of bloat is a sudden onset of abdominal distention, distress, anxiety and pain (panting, guarding the belly, anguished facial expression), and multiple attempts at vomiting that are frequently unproductive.

Not every dog will have a classic appearance and some dogs will not have obvious abdominal distention because of their body configuration.  If you are not sure, it is best to err on the side of caution and rush your dog to the veterinarian immediately.

There are several steps to saving a bloated dog’s life.  Part of the problem is that all steps should be done at the same time and as quickly as possible.

The huge stomach is by now pressing on the major blood vessels carrying blood back to the heart. This stops normal circulation and sends the dog into shock.  Making matters worse, the stomach tissue is dying because it is stretched too tightly to allow blood circulation through it.  There can be no recovery until the stomach is untwisted and the gas released.  A stomach tube and stomach pump are generally used for this, but sometime surgery is needed to achieve stomach decompression.

Intravenous catheters are placed, and life-giving fluid solutions are rushed in to replace the blood that cannot get past the bloated stomach to return to the heart.  The intense pain associated with this disease causes the heart rate to race at such a high rate that heart failure will result.  Medication to resolve the pain is needed if the patient’s heart rate is to slow down.  Medication for shock, antibiotics and electrolytes are all vital in stabilizing the patient.

A special and very dangerous rhythm problem, called a premature ventricular contraction, or "PVC," is associated with bloat and it must be ruled out.  If this is the case, intravenous medications are needed to stabilize the rhythm.  Since this rhythm problem may not be evident until even the next day, continual EKG monitoring may be necessary.  If the disturbed heart rhythm is noted at the very beginning of treatment, this is associated with a 38 percent mortality rate.

All bloated dogs, once stable, should have surgery.  Without surgery, the damage done inside cannot be assessed or repaired, plus bloat may recur at any point, even within the next few hours, and the above care must be repeated.  If the stomach has not untwisted with decompression, the surgeon untwists it and determines what tissue is viable and what is not.  If there is a section of dying tissue on the stomach wall, this must be discovered and removed, or the dog will die despite the treatment described above.

Also, the spleen, which is located adjacent to the stomach, may twist with the stomach necessitating removal of the spleen or part of the spleen as well.  After the nonviable tissue is removed, a surgery called a gastropexy is done to tack the stomach into its normal position to prevent future twisting.

After the expense and effort of the stomach decompression, it is tempting to forgo the further expense of surgery.  However, consider that the next time your dog bloats, you may not be there to catch it in time and, according to the study described below, without surgery there is a 24 percent mortality rate and a 76 percent chance of re-bloating at some point.  The best choice is to finish the treatment that has been started and have the abdomen explored.  If the stomach can be surgically tacked into place, recurrence rate drops to 6 percent. Surgery will prevent the stomach from twisting in the future, but the stomach is still able to periodically distend with gas.  This is uncomfortable but not life-threatening.

It is crucially important that the owners of big dogs be aware of this condition and prepared for it.  Know where to take your dog during overnight or Sunday hours for emergency care.  Avoid exercising your dog after a large meal.  Know what to watch for.  Enjoy the wonderful comradery a large dog provides but at the same time be aware of the large dog's special needs and concerns.

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