Gastric Dilatation/Volvulus (GDV)

By Nancy Otten, Animal Health Technologist

What is GDV?

When we use the word gastric we are referring to the stomach.  Dilatation, or dilation, means that something is being stretched beyond its normal dimensions.  Volvulus occurs when an organ, most commonly a section of intestine, twists causing a blockage and often cutting off blood supply.  GDV, then, is when the stomach becomes enlarged, usually with air, and then twists on itself.  The common name for GDV is bloat. 

Why is GDV so serious? 

The bloat that the dog is experiencing is more serious than the bloat we feel when we eat too much.  This bloat won’t go away with time and causes serious damage.  When the stomach becomes much distended, it puts pressure on surrounding tissues.  The caudal vena cava and the portal vein, large veins that carry blood back to the heart, run along the stomach.  When the stomach is bloated excessively, it compresses these veins and prevents blood from getting back to the heart.  This greatly diminishes the output of blood from the heart which deprives the body of oxygen.  This oxygen deprivation causes the body to go into shock.  The blood vessels involved in oxygenating the stomach itself become compressed from the pressure and the twisting and are thus unable to perfuse the organ with the needed oxygenated blood.  This can cause tissue death.  The spleen runs along the stomach and is attached to the stomach wall.  The twisting cuts off blood supply to this organ causing tissue death as well.  Also, when the stomach contents can’t move into the intestines, toxins build up.  This causes inflammation of the stomach wall which allows these toxins to enter the bloodstream.  This may lead to a fatal phenomenon called DIC (disseminated intravascular coagulation) where the dog’s blood clots inappropriately within the bloodstream.      

What causes GDV?

We don’t really know why GDV occurs but we do know what predisposes dogs to developing it.  Research done at Purdue University found five factors that may predispose your dog to GDV.  The first, and most important, is chest size.  Dogs with deep chests (not broad, but narrow and deep) are much more likely to develop GDV.  Commonly affected breeds are Great Danes, German Shepherds, Standard Poodles, Irish Setters, Afghan Hounds, and any large mixed breed dog.  Using a raised food bowl also greatly predisposes your pet to GDV.  This is ironic because for years it was recommended to use a raised food bowl as GDV prevention.  The next predisposing factor is genetics.  If the dog has a first degree relative (i.e. a parent or sibling) that has had GDV before, it greatly increases his risk for developing the condition as well.  The study also found that the incidence of GDV increases with the dog’s age.  The speed at which your dog eats may also affect his incidence of developing the condition.  The faster he eats, the more likely he is to develop GDV. 

Some other predisposing factors have been suggested.  There seems to be a correlation between highly processed foods and GDV.  Shar peis seem to be predisposed to bloat, despite the fact that they don’t have the deep chest of the dogs that are normally associated with this disorder.  Dogs with a history of sensitive stomachs (have frequent episodes of vomiting and diarrhea) seem to have more problems with GDV.  Food may empty out of the stomachs more slowly allowing more gas to accumulate in the stomach.  Similarly, it is widely believed that exercise an hour before or after feeding may predispose a dog to GDV.  Exercise diverts blood away from the digestive tract and therefore slows it down.  The longer food sits in the stomach, the more gas accumulates which may lead to GDV.

What are the symptoms of GDV?

Sudden onset abdominal distention is the most common symptom.  The dog’s abdomen will visibly expand within a couple of hours and will be quite firm to the touch.  It should be noted that sometimes a portion of the dog’s stomach may be tucked up under the ribs preventing an obvious distention.  In most cases, however, the distention will be obvious.

The dog may also exhibit unproductive retching and belching, hypersalivation, restlessness, and respiratory distress.

How is GDV treated?

The seriousness of this condition cannot be stressed enough.  If you suspect that your dog is experiencing GDV, rush him to a veterinarian immediately.  There is no time to waste.  If your dog is in shock the veterinarian will need to stabilize the dog first by infusing large quantities of intravenous fluids.  An x-ray will be necessary to determine if the stomach is merely distended or if there is volvulus involved.  If it is determined that the stomach is not twisted, the veterinarian may attempt to pass a tube down the esophagus and into the stomach to relieve the pressure.  If it is twisted, a large bore needed can be inserted into the stomach through the abdominal wall to relieve the pressure.  When the animal is stabilized, surgery will be needed.  The stomach and spleen will need to be returned to their proper positions and will need to be inspected for tissue death.  Any dead tissue will need to be removed.  The veterinarian will then perform a procedure called a gastropexy where the stomach is fixed to the abdominal wall to prevent the reoccurrence of GDV. 

How can we prevent GDV?

There is evidence suggesting that dogs that eat quickly are more susceptible to developing GDV.  The following are some suggestions to slow them down a bit: if you have more than one dog, feed them in separate rooms (the absence of competition for food may slow them down); place their food on a flat baking sheet so that they can’t grab big mouthfuls; place a large stone (too large to swallow) in the middle of their dish so that they have to work around it to get at their food; feed them at least twice a day so they aren’t so hungry at feeding time.  There is also evidence that raised food bowls may be problematic.  Make sure their food bowls are at ground level.  Finally, don’t exercise your dog during the hour before or after feeding.