Rob Hilsenroth, DVM
Have you ever felt bloated? It’s a condition that many have experienced after eating – that uncomfortably full feeling in your stomach after a big meal or after eating foods that result in a lot of gas production. Bloat for us is unpleasant, but it’s usually a transient, uncomplicated condition.
Bloat in dogs, however, is a completely different condition, with very severe ramifications. In certain breeds of dogs, when the stomach fills with air, it can get so large that it can interfere with breathing, impede circulation, and result in shock. The episode doesn’t necessarily follow eating a big meal. In many instances, a bloated stomach can twist upon itself, causing a life-threatening condition known as gastric dilation and volvulus, or GDV. Regardless of what we call it, bloat or GDV, it’s a serious condition that requires immediate veterinary attention. For the rest of this article we’ll use the term bloat.
Canine bloat occurs most often in purebred dogs that have deep and narrow chests and abdomens. Such breeds as Great Danes, Irish Setters, Saint Bernards, Doberman Pinchers, and Basset Hounds top the list of those at highest risk for developing bloat.
Canine bloat is a distressing disease for dog and owner alike. It often happens to dogs that are otherwise normal and healthy. The onset of the condition is sudden and very painful for the affected dog. Bloat can occur at any age, but older dogs tend to be affected more often. Canine bloat should be considered an emergency situation.
What causes canine bloat?
The exact cause of bloat in dogs is unknown. The reasons why and when bloat is likely to happen are questions that scientists are still trying to answer. Veterinarians believe that bloat is probably caused by several different factors. The most consistent finding is its occurrence, as mentioned above, in dog breeds with deep, narrow chests. Inherited or genetic traits may account for part of a dog’s risk of developing bloat.
Any of a large number of circumstances that can result in excessive amounts of gas or air in the stomach can also con-tribute to canine bloat. Many veterinarians believe that dogs who consume their food ravenously, or those who consume large amounts of food or water at one time are at higher risk of bloating, although this has not been proven.
Swallowed air also contributes to the amount of air in the stomach. Large amounts of air in the stomach may cause it to rise into an unusual position that can lead to the stomach twisting upon itself. This twist of the gas-filled stomach will cut off the vital blood supply to the affected portion of the stomach and cause death unless the twist is corrected.
What are the signs of canine bloat?
The most noticeable sign of bloat is a rapidly enlarging midsection, right behind the rib cage. This enlargement takes place over a period of minutes to hours. Some dogs, however, don’t show any swelling, but will look and act uncomfortable. Most dogs usually have pain in the abdomen, and may walk around with difficulty. Unproductive vomiting, pale gums, and a rapid heart rate with weak pulse rate are also common signs of bloat.
How is canine bloat diagnosed and treated?
The initial diagnosis of bloat is usually made on physical examination by the veterinarian, and it can be confirmed by abdominal radiographs. Passage of a gastric tube is a procedure that can be both diagnostic and therapeutic. It can confirm the presence of gas trapped in the stomach, and it can help to relieve the pressure in the stomach. If the tube can’t be passed all the way to the stomach, it’s often an indicator that a torsion has occurred.
To treat a dog with bloat, the veterinarian must first correct the shock that is present and is the most life-threatening situation. Shock follows the compromise of the circulatory system and the inability of blood to reach the vital organs.
To treat this condition, large amounts of fluid must be administered intravenously to increase the circulatory blood volume. Next, the stomach must be decompressed. If this can’t be accomplished with the gastric tube, a procedure called trocharization is attempted. This involves inserting a large needle directly into the stomach through the body wall. This will have an effect similar to that of letting the air out of a big balloon and will provide temporary relief.
The definitive treatment for bloat is surgery to correct the twist and remove any portion of the stomach that may have been irreversibly damaged. If the stomach has ruptured due to excessive stretching, the prognosis for recovery is extremely poor.
Given the propensity for some dogs to bloat, most surgeons will perform a technique called a gastropexy when they correct a twisted stomach. This procedure affixes the stomach in place by attaching it to the abdominal wall. The aftercare of the bloat patient is also extremely important. Dogs must remain hospitalized with fluids for several days before they can gradually be reintroduced to solid foods.
What is being done about canine bloat?
Morris Animal Foundation recognizes that bloat is a serious condition that happens frequently in many dog breeds. The Foundation is currently sponsoring the study “Prospective Study of Morphometric, Genetic, and Dietary Risk Factors for Bloat” by Dr. Larry Glickman at Purdue University School of Veterinary Medicine.
Dr. Glickman and his colleagues are investigating the influence of factors such as diet, heritability, and body structure of several high-risk breeds for canine bloat. Dr. Glickman’s efforts will provide valuable knowledge to breeders and owners about the factors that may cause bloat in dogs at high risk for developing this dreadful condition.
Cosponsors of this study are Morris Animal Foundation, the AKC Health Foundation, “Piedde Boue” Working Bouviers (in memory of Chelsea), and the Hill’s Mark L. Morris Lifetime Achievement Award honoring Anne Rogers Clark.
Rob Hilsenroth, DVM, is Executive Director of Morris Animal Foundation. This nonprofit organization sponsors animal health studies at veterinary schools and institutions throughout the U.S. and in other parts of the world. All annual unrestricted contributions to the foundation support health programs – not the cost of administration or fund-raising.
If you’d like to make a contribution, write Morris Animal Foundation, 45 Inverness Drive East, Englewood CO 80112. For more information, call (800) 243-2345.