Dog Gastric Dilatation Volvulus (Bloat)

Gastric Dilatation-Volvulus (GDV) is a serious and life-threatening condition that requires prompt medical stabilization followed by surgical intervention. Although it is primarily a condition of large and giant breeds, it has been reported in small breeds (dachshund, miniature poodle, Scottish terrier).

In most cases the cause of GDV remains unknown but it's cardiovascular, clincopathologic and gastrointestinal effects have been well documented in the literature.

Signs of GDV
GDV usually affects large breed dogs that show the following signs: distended abdomen, excessive salivation, restlessness, nonproductive retching and signs of shock (depression, pale gums, increased heart rate). To truly confirm the diagnosis of GDV requires radiographs (x-rays) or surgical exploration.

Emergency Medical Treatment
If you suspect your pet is showing signs of GDV then prompt medical attention should be sought out. Dogs with GDV usually present with mild to severe signs of hypovolemic shock. It is treating the hypovolemic shock that is critical in stabilizing the dogs prior to surgery.

Emergency treatment will begin with shock therapy that consists of intravenous fluid therapy, the type fluids will depend on the veterinarians choice.

Once appropriate fluid therapy has initiated other considerations for treatment of GDV should consist of steroids, appropriate antibiotic therapy and therapy for endotoxemia. Once shock therapy has been initiated then gastric decompression can be attempted. This is done with either the passage of an orogastric tube and if unsuccessful then trocharization, placing a needle into the stomach through the body wall.

Surgery
During surgery there are three main goals that are addressed: 1) Derotation of the stomach, 2) Assess gastric wall viability, and 3) permanent gastropexy. In most cases the stomach can be fairly easy to derotate if it has been adequately decompressed. Once this has been accomplished the difficult task of assessing gastric wall viability begins.

When the stomach rotates, vascular changes occur that can lead to gastric wall damage. It is the job of the surgeon to assess the stomach wall viability and determine if partial gastric removal is required. It has been reported that approximately 10% of cases of GDV require partial gastrectomy. The problem facing surgeons is an accurate way to determine viable stomach wall.

Currently subjective techniques of assessing gastric wall viability include color, perfusion, vascular patency and palpation. Once the gastric wall viability has been determined then the final step of gastropexy can be attempted. There has been four techniques mainly described in the literature and they are tube gastrostomy, incisional, circumcostal and belt-loop gastropexy.

Tube gastrostomy is a fairly simple and fast technique where a tube is inserted through the body wall on the right side 2-3 cm from midline. Its advantages are that it allows for continual gastric decompression as well as gives a route for medication and food if the dog is inappetant post operatively.

Its disadvantages are it has the potential for development of septic peritonitis due to leakage around the tube site and it usually is associated with more morbidity requiring a longer hospital stay.

Incisional gastropexy is a simple and easy technique to perform and is the technique that I use for GDV. The advantages are that it is easy and fast, has a strong mature adhesion form over time and does not involve entering the gastric lumen.

The disadvantages are that it is weaker then a circumcostal or belt loop technique and that it does not provide continual decompression.

The circumcostal technique was one of the first techniques described for GDV surgery. The advantages are a very strong pexy site and the technique does not enter the lumen of the gastric lumen.

The disadvantages are that there is the possibility of causing a pneumothorax, more time consuming and possible rib fracture.

The belt loop technique utilizes a 2.5 cm by 4 cm seromuscular flap created in the area of the pyloric antrum. The advantages of this technique are similar to the incisional and circumcostal gastropexy.

Post operative management
There are many concerns post-operatively with GDV surgery and these animals should have 24-hour monitoring. These animals should be kept on continual fluid therapy with adequate potassium. Appropriate pain medication should also be given. I routinely begin my GDV patients on GI protectants which include an H2 blocker. Appropriate antibiotic therapy should be maintained post operatively especially if endotoxemia is present or there was a rupture stomach and associated peritonitis.

Other post-operative complications can occur especially with the heart. Cardiac arrhythmias can occur and are usually ventricular in origin. These arrhythmias can be life threatening and these patients should have continual ECG monitoring. The most common arrhythmia seen is ventricular premature contracture (VPC).

Prevention
Owners of large and giant breed dogs should avoid diets high in carbohydrates, feed small frequent meals instead of one or two large meals and avoid heavy exercise after eating. There are many out there performing prophylactic gastropexies on animals and although this should prevent the occurrence of GDV it will not prevent gastric dilatation.

By Gregory Herndon, DVM