Gastric Dilation Volvulus
What is GDV (Bloat)?
GDV is a very much more descriptive term than the old fashioned name, bloat, which is still often used for the condition in farm animals. It means 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?
The definite cause is still unknown. 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 resulting in fermentation and gas formation. However we know that many dogs will develop the condition during the night when they are resting. Today aerophagia (the swallowing of air) is thought to play as important a part as fermentation of stomach contents. In addition there may be a disruption of the normal contractions of the stomach. This allows fermentation and further gas accumulation. Sometimes the condition 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 occluded. This is gastric torsion.
Is this as serious as it appears?
Yes. This is probably one of the most serious non traumatic conditions. Veterinary help is needed without delay.
Are some dogs more prone than others?
Yes, statistically we know that large, deep chested breeds are more prone to GDV. These include German Shepherd Dogs, Great Danes, Setters etc. Most commonly the condition occurs two to three hours after eating a large meal.
These are the facts:-
· The condition almost always occurs in deep chested dogs of giant or large breeds
· Gastric dilatation, usually without volvulus (torsion), occasionally occurs in elderly small dogs, e.g. Dachshunds
· The distending stomach pushes the posterior 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 swelling stomach presses on the diaphragm and breathing becomes laboured
· The swollen stomach also presses on the larger blood vessels in the abdomen and circulation is seriously compromised, resulting 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 dilation (GD) and gastric dilation and volvulus (GDV)?
No. Very often on initial clinical examination a veterinary surgeon cannot distinguish, x-rays 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 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 and may be delayed until the patient is stabilised.
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 upon itself 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 carried out
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 rate of 15-20% for 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. This does not prevent dilatation (bloat) but does prevent twisting (volvulus) in the majority of cases.
Careful attention to diet, feeding and exercise regimens help to prevent dilatation.
Please do not hesitate to contact us to discuss any concerns you have regarding this difficult condition.