Bloat, Canine

 Bloat (Gastric Dilatation Volvulus)
By Dr. Karen Burgess

What is bloat?
GDV (gastric dilatation and volvulus) is commonly referred to as bloat.  Technically bloat is when the stomach becomes overly distended with air or material (food typically).  Bloat alone can be range from causing abdominal pain to being life threatening.  In some cases, particularly in large or deep chested breeds, the bloated stomach can then twist upon itself thereby cutting off its blood supply and in some cases that of the spleen too.  This would be a case of torsion or volvulus is always an emergency and potentially life threatening.

Why do dogs develop GDV?
There is not one reason that dogs develop gastric torsion.  It is more common in giant breed (60% of Great Danes and 20% of dogs over 100# will experience GDV during their lifetime), deep chested, older and stressed or excited dogs.  There is also thought to be some correlation with eating a large meal and bloat occurring two to three hours later.

What problems does bloat and GDV (torsion) cause?
Both syndromes can affect blood supply to the stomach.  With torsion this is typically more severe and in a very short time circulation can be diminished to a point where the stomach wall actually dies.  Shock and severe pain are also common with GDV leading to potential circulatory collapse and death.

What are the signs of bloat and GDV (torsion)?
To the naked eye both will look very similar.  A distended abdomen may be noted and typically the pet will repeatedly vomit or appear to dry heave.  Sudden sever pain, lethargy, weakness, or collapse may also occur.  Testing is necessary to accurately differentiate between the two syndromes.  If symptoms are noted the pet should be taken immediately to a veterinarian.

What will the veterinarian do?
GDV is a life threatening emergency and immediate intervention is essential to improve chances of treatment success.  Dogs suspected of being bloated will often be triaged and immediately taken to a treatment area for care and diagnostics.  An intravenous catheter will be placed and large volumes of fluids administered to reverse signs of shock.  Pain medication is often provided and evaluation of vital signs performed to evaluate for life threatening heart arrhythmias.  The stomach may be trocarized (have a needle placed externally) or a stomach tube passed to allow immediate release of pressure.  Radiographs are taken to help differentiate between the two conditions.  Labwork is performed to determine the impact on the remainder of the body systems.  A discussion will be had on treatment options.

How is GDV (torsion) treated?
Unfortunately the stomach does not often return to normal position even if pressure is released externally.  There is also often secondary damage to the spleen or stomach wall.  Surgery is the only definitive treatment for GDV.  An abdominal exploratory is performed and internal organs examined.

The stomach is untwisted and evaluated.  It is not uncommon for the spleen to also be affected and require removal.  The stomach wall is then sutured to the body wall (gastropexy) thereby preventing future episodes.  While the pet may still experience bloat, torsion is unlikely.  Without a gastropexy nearly all dogs that experience GDV will have another episode.

What is the prognosis?
This depends a great deal on many factors.  There are several expected complications associated with GDV and mortality rates in uncomplicated cases can be as high as 20%.

How can GDV be prevented?
Prophylactic gastropexy (tacking the stomach to the body wall thereby preventing torsion) is often recommended at the time of spay or neuter in breeds considered at risk.