Bloat is a very serious health risk for many dogs, yet many
dog owners know very little about it. It is frequently
reported that deep-chested dogs, such as German Shepherds,
Great Danes, and Dobermans are particularly at risk.
technical name for bloat is "Gastric Dilatation-Volvulus" ("GDV").
Bloating of the stomach is often related to swallowed air
(although food and fluid can also be present). It usually
happens when there's an abnormal accumulation of air, fluid,
and/or foam in the stomach ("gastric dilatation"). Stress
can be a significant contributing factor also. Bloat can
occur with or without "volvulus" (twisting). As the stomach
swells, it may rotate 90° to 360°, twisting between its fixed
attachments at the esophagus (food tube) and at the duodenum
(the upper intestine). The twisting stomach traps air, food,
and water in the stomach.
The pressure on the diaphragm
makes it difficult for the dog to breathe. The air-filled
stomach also compresses large veins in the abdomen, thus
preventing blood from returning to the heart. Filled with air,
the stomach can easily rotate on itself, thus pinching off its
blood supply. Once this rotation (volvulus) occurs and the
blood supply is cut off, the stomach begins to die and the
entire blood supply is disrupted and the animal's condition
begins to deteriorate very rapidly and the combined effects
can quickly kill a dog.
gastric distention can occur in any breed or age of dog and is
common in young puppies who overeat. This is sometimes
referred to as pre-bloat by laymen. Belching of gas or
vomiting food usually relieves the problem.
condition occurs more than once in a predisposed breed, the
veterinarian might discuss methods to prevent bloat, such as
feeding smaller meals or giving Reglan (metoclopramide) to
encourage stomach emptying. Some veterinarians recommend, and
some owners request, prophylactic surgery to anchor the
stomach in place before the torsion occurs in dogs who have
experienced one or more bouts of distention or in dogs whose
close relatives have had GDV.
The exact cause of GDV has never been resolved
but theories abound. One theory claims some dogs are born with
their stomachs slightly out of position allowing it to twist
more easily. Another theory speculates affected dogs are born
with impairment of either the esophagus or pylorus,
effectively preventing food from leaving the stomach. Dogs
that gulp food and then exercise heavily may also be at
increased risk. Some dogs under extreme anxiety suffer
"stress-related bloat" by gulping large amounts of air when
nervous. Tumors of the spleen, stomach, kidney or other
internal organs, may cause twisting and subsequently result in
bloat. Eating indigestible materials like clothing or garbage
may also cause bloating.
Studies have been ongoing at many veterinary
schools for decades but the exact cause(s) remains a mystery.
The frequency of bloat has been estimated at 2.9 to 6.8 cases
per 1,000 dogs. Dogs seven years and older appear to be twice
as likely to bloat as dogs among 2 and 4 years old. Purebred
dogs are 3 times more likely to bloat then mixed breeds.
The earliest clinical signs of a dog suffering
...Restlessness. The dog will act anxious,
agitated, uncomfortable, and unable to rest.
...Loss of appetite. It may not be interested
in food or water, though some dogs dry to drink.
...It may vomit once or twice followed by
nonproductive retching and gagging. It may
attempt to defecate.
...Whining, crying, heavy panting, and
salivation accompany the physical distress.
If your dog exhibits any of the above mentioned
symptoms, transport the animal to your vet or to an Emergency
Clinic without delay. Treatment is aimed at stabilizing shock,
and relieving gas pressure. Surgery should be performed to
turn the stomach back to its normal position, remove necrotic
tissue and finally, to tack the stomach (gastropexy) to
prevent a recurrence of torsion. Once a dog bloats, it will
bloat again and torsion or twisting will recur if surgery is
not performed following the first GDV episode.
Twenty-nine to thirty-three percent of all dogs
with GDV die. Survival depends on how quickly the owners get
the dog in for emergency care, how experienced your
veterinarian is in treating the disease and luck. Shock, heart
arrhythmias, a build-up of metabolic poisons and
post-operative infection are the primary causes of death with
GDV. These dangerous post-bloat effects can occur for at least
7 days following the GDV episode and surgery.
Despite adopting all of the recommendations listed below, a
dog may still develop GDV.
- Owners of susceptible breeds
should be aware of the early signs of bloat and contact
their veterinarian as soon as possible if GDV is suspected.
- Owners of susceptible breeds
should develop a good working relationship with a local
veterinarian in case emergency care is needed.
- Large dogs should be fed two or
three times daily, rather than once a day.
- Water should be available at all
times, but should be limited immediately after feeding.
- Vigorous exercise, excitement, and
stress should be avoided one hour before and two hours after
- Diet changes should be made
gradually over a period of three to five days.
- Susceptible dogs should be fed
individually and, if possible in a quiet location.
- Some studies suggest that dogs who
are susceptible to bloat should not be fed with elevated
feeders; other studies have not found this to be true. It is
recommended, however, that dogs at increased risk be fed at
- Some studies have associated food
particle size, fat content, moistening of foods containing
citric acid, and other factors with bloat. At this time, no
cause-and-result relationships between these factors and
bloat have been verified.
- Dogs that have survived bloat are
at an increased risk for future episodes; therefore
prevention in the form of preventive surgery or medical
management should be discussed with the veterinarian.
Beck, JJ; Staatz, AJ; Pelsue, DH;
Kudnig, ST; MacPhail, CM; Seim HB; and Monnet, E. Risk factors
associated with short-term outcome and development of
perioperative complications in dogs undergoing surgery because
of gastric dilatation-volvulus: 166 cases (1992-2003). Journal
of the American Veterinary Medical Association,
Ellison, GW. Gastric dilatation
volvulus: An update. Presented at the Western Veterinary
Conference, Las Vegas NV, 2004.
Glickman, LT; Glickman, NW;
Shellenburg, DB; et al. Multiple risk factors for the GDV
syndrome in dogs: A paractitioner/owner case control study.
Journal of the American Animal Hospital Association, 1997, 33:
Monnett, E. Gastric dilatation
volvulus. Presented at the Western Veterinary Conference, Las
Vegas NV, 2002.
Simpson, KW. Diseases of the stomach.
In Ettinger, SJ; Feldman, EC. Textbook of Veterinary Internal
Medicine. W.B. Saunders Co. Philadelphia, PA; 2005: 1319-1321.