The Big, Bad, Bloat!
Bloat / Gastric Dilatation and Volvulus (GDV)
Of all veterinary medical emergencies, nothing strikes fear in the heart of veterinarian like a good GDV emergency. One of the internal medicine clinicians in my veterinary school loved to dramatically rush into the third-year surgery on-call room at 4:30 pm and announce, “There’s a GDV on the way!” and run away laughing hysterically as the poor surgery students would rush around prepping for this serious emergency. This particular emergency is set apart from the rest due to the seriousness of it’s presentation, the complexity and rapidity of its consequences for our patients. Our staff must act very quickly and very precisely, together as a well-oiled machine, to ensure the best outcome for these patients.
What is GDV and why is it so serious?
In the dog, the normal stomach sits high within the abdominal cavity and contains a small amount of gas, some mucus, and any food that is being digested. It undergoes a normal rhythm of contraction, receiving food from the esophagus above, grinding up the food particles, and passing the food material into the intestine located at the opposite end of the stomach.
In the bloated stomach, stomach contents (gas, food or liquid) cause the stomach to stretch well beyond its normal size, which causes the patient tremendous abdominal pain. For reasons that are not entirely understood, the grossly distended stomach will begin to rotate, which causes the stomach to cut off its own blood supply, as well as occlude the exit route for the material within the stomach. Due to its close proximity to the greater curvature of the stomach, the spleen can become twisted as well, which cuts off the circulation of this organ as well. The distended stomach can become so large that it compresses the large veins that run along the back and return the body’s blood to the heart. This is creates circulatory shock, at which point this condition becomes a rapidly life-threatening emergency. A dog with a bloated, twisted stomach will die within a matter of hours unless drastic steps are taken very quickly.
What are the risk factors for developing bloat (GDV)?
This condition most commonly affects deep-chested dog breeds, meaning that the length of their chest from the backbone to the sternum is relatively long, while the width of the chest from left to right is quite narrow. Examples of deep-chested dog breeds would be the Great Dane, Greyhound, German Shepherd, Doberman Pinscher, Weimaraner, Saint Bernard, etc. Still, any dog can bloat, even dachshunds and chihuahuas. The risk of bloat also increases with age.
Classically, the bloated dog has recently eaten 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 increased risk of bloat. Some factors round to increase and decrease the risk of bloat are listed below:
Factors that increase the risk of bloat –
- Feeding only one meal a day
- Having closely related family members with a history of bloat
- Eating rapidly
- Being thin or underweight
- Moistening dry foods (particularly if citric acid is listed as a preservative)
- Restricting water before and after meals
- Feeding a dry diet with animal fat listed in the first four ingredients
- Fearful or anxious temperament
- History of aggression towards people or other dogs
- Male dogs are more likely to bloat than females
- Older dogs (7-12 years) were the highest risk group
Factors that decrease the risk of bloat –
- Waiting an hour after feedings for exercise
- Slow-feeder bowls
- Pacing water intake
- 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
- Happy or easy-going temperament
- Including canned food in the diet
Contrary to popular belief, cereal ingredients such a soy, wheat, or corn in the first four ingredients of the ingredient list do not increase the risk of bloat.
Signs of bloat in the dog
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 non-productive. Not every dog will have a classic presentation, and some dogs may not have obvious abdominal distention because of their body configuration. If you are not sure, it is still best to err on the side of caution and rush your dog to the veterinarian IMMEDIATELY.
Radiographs will need to be taken to distinguish bloat from other potential emergencies (such as sudden abdominal hemorrhage from a ruptured tumor) that might have a similar presentation. The image above shows the severely distended stomach and the classic “double bubble” sign where the stomach is divided into two gas-filled sections because of the twist (volvulus) that makes this a serious emergency.
Treatment
The first goal is to stabilize the patient, which involves multiple steps at once.
FIRST: The stomach much be decompressed
The hugely distended stomach is by now pressing on the major blood vessels that carry blood back to the heart. This stops the dog’s normal circulation and pushes the dog into shock. In addition, the stomach tissue is dying because it is stretched too tightly to allow blood circulation through it. A stomach tube is passed through the mouth and esophagus to relieve the fluid and gas within the stomach, and de-rotate the twisted stomach.
ALSO FIRST: Rapid IV fluids must be administered to reverse shock
Large-bore intravenous catheters are placed in a minimum of two limbs and life-giving fluid solutions are rushed into the body to replace the blood that cannot get past the bloated stomach to return to the heart. The intense pain associated with this condition causes the heart rate to race at such a high rate that heart failure will result. Mediation to resolve the pain is needed to help bring the patient’s heart rate down to a stable rate. Medication for shock, antibiotics and electrolytes are also all vital in stabilizing the GDV patient.
ALSO FIRST: The heart rhythm is assessed and stabilized
A very dangerous heart arrhythmia, called a premature ventricular contraction or PVC, is associated with GDV, and it must be treated. Intravenous medications are administered to stabilize the rhythm. Since this arrhythmia may not be evident until even the next day, continual EKG monitoring may be necessary.
Surgery
Decompressing the bloated dog’s stomach, and stabilizing the shock, is only the start of treatment. All bloated dogs, once stable, should have surgery immediately. Without surgery, the damage done inside cannot be accurately assessed or repaired. In addition, bloat can easily recur at any point, even within the next few hours, and the above adventure of decompression and stabilization must be repeated.
If the stomach was not successfully untwisted with decompression, the surgeon will first untwist the stomach and then determine if the stomach tissues are viable. If there is a section of dying stomach wall, this must be discovered and surgically removed or the dog will die despite the heroic efforts of stabilization. In addition, the spleen, which is located adjacent to the stomach, may twist along with the stomach requiring removal of the spleen. After the nonviable tissue is removed, a surgery called a gastropexy is performed to tack the stomach to the body wall in its normal position to prevent it from twisting ever again.
Without surgery, there is a 24% mortality rate and a 76% chance of bloat occurring again at some point. The best choice is to finish the treatment that has been started and have the abdomen surgically explored. If the stomach can be surgically tacked into place, recurrence rate drops to 6%. While surgery will prevent the stomach from twisting in the future, the stomach will still be able to periodically distend with gas. While this is uncomfortable, it is not life-threatening.
Prevention
Preventative gastropexy is an elective surgery usually performed at the time of spay or neuter in a breed that is considered to be at risk for GDV. The gastropexy, as mentioned before, tacks the stomach to the body wall so that it cannot twist and cause a life-threatening emergency. The stomach may still distend with gas in an attempt to bloat, but since it is unable to twist, this can be painful and uncomfortable for the dog, but not life-threatening. This prophylactic surgical procedure is far less expensive than an emergency GDV surgery, and can and will save the life of patients that fall into the category of high-risk breeds. Talk to your veterinarian to discuss whether or not your large-breed dog is a candidate for this elective procedure.
