Dog - Gastric Dilatation Volvulus (GDV)

What is GDV (bloat)?

Gastric dilatation-volvulus (GDV) is more descriptive than the original term bloat although this term is still commonly used when the condition occurs in farm animals. GDV indicates the dog’s stomach is distended with gas and may in addition have twisted upon itself thus effectively trapping the gas in the stomach. Bloat refers solely to a gas filled stomach.

What causes the condition?

Cause is still uncertain in many cases. Theories abound, the most common suggests that the cause is due to eating a large meal and drinking a lot of water following strenuous exercise. This results in fermentation and gas formation. However, we know that many dogs will develop the condition during the night when they are resting. Aerophagia (the swallowing of air) may play as important a part as fermentation of stomach contents. In addition there may be a disruption of the normal contractions of the stomach thus allowing fermentation and further gas accumulation. The condition sometimes progresses no further than simple dilatation (bloat) whereas in other instances the huge gas filled stomach twists upon itself so that both entrance and exit (cardia and pylorus) are effectively plugged. This is gastric torsion, a twisted stomach.

Is this as serious as it appears?

Yes. This is probably one of the most serious non traumatic conditions to affect dogs. Veterinary help is needed urgently.

Are some dogs more prone than others?

Yes, statistically we know that large, deep chested breeds are more prone to GDV. These include popular breeds such as German Shepherd dogs, Great Danes and Setters. Most commonly the condition occurs 2-3 hours after eating a large meal.

What else is known about the condition?

• The condition almost always occurs in deep chested dogs of large or giant breeds.
• Most commonly the condition occurs 2–3 hours after eating a large meal particularly if it follows strenuous exercise.
• Gastric dilatation, often without volvulus (torsion), occasionally occurs in elderly small dogs, e.g. Dachshunds.
• The distending stomach pushes out the posterior (back end) rib cage so that the dog appears swollen. This is most obvious on the left side and gentle tapping of the swelling just behind the last rib often produces hollow drum-like sounds.
• The rapidly swelling stomach also presses on the diaphragm making breathing increasingly laboured.
• The swollen stomach also presses on the larger blood vessels in the abdomen causing circulation to be seriously restricted. This results in profound shock.
• Finally the dog collapses and once on its side (lateral recumbency) the huge size of the abdomen can be appreciated.

Is it possible to distinguish between gastric dilatation (GD) and gastric dilatation-volvulus (GDV)?

No. Very often on initial clinical examination the vet cannot be sure. X-rays (radiographs) and other tests will establish whether or not the stomach has twisted.

Why does the dog collapse?

The gas filled stomach, presses on the large veins in the abdomen that carry blood back to the heart. Tissues are deprived of blood and therefore oxygen. This causes the dog to go into shock. In addition, the pressure of the gas on the stomach wall results in inadequate circulation and the stomach wall can quickly begin to die and may rupture. Digestion ceases, toxins accumulate and are absorbed so increasing the shock.

What can be done?

• Veterinary assistance must be sought immediately.
• It is imperative that the pressure on the stomach wall and internal organs is reduced and to do this the veterinary surgeon may attempt to pass a stomach tube. If this is not possible due to twisting of the stomach, a large bore needle may be passed through the skin into the stomach.
• At the same time it is imperative to treat shock with the administration of large quantities of intravenous fluids (a drip) and therefore an intravenous line will be rapidly established.
• Once the patient has been stabilised, the stomach must be returned to its proper position. This involves major abdominal surgery.

What is done at operation?

• The stomach has to be returned to its natural position and recurrence has to be prevented by means of a technique called gastropexy. This involves attaching the stomach wall to the abdominal wall so that it cannot twist again. At the same time the stomach is inspected to detect areas of necrosis (death) of the wall. If this has occurred further surgery may be necessary to remove the dead tissue.
• As a result of the shock due to the interference with the blood supply heart abnormalities may be detected and monitoring by means of an electrocardiogram (ECG) is often required.

What is the survival rate?

This depends upon the circumstances, e.g. degree of shock, the severity of the condition, cardiac problems, stomach wall necrosis, length of surgery etc.

Even in relatively uncomplicated cases there is a mortality (death) rate of 15-20% with GDV.

Can the condition be prevented?

Gastropexy (surgical attachment of stomach to body wall) is the most effective means of prevention. In particularly GDV prone strains of deep chested dogs, it is sometimes recommended for prophylaxis (prevention). This does not prevent dilatation (bloat) but does prevent twisting (volvulus) in the majority of cases.

Careful attention to diet, feeding and exercise all help to prevent this potentially life threatening condition.

Please do not hesitate to contact us regarding any concerns or worries you may have regarding GDV. We will be pleased to discuss problems with you.