CONDITION
Gastric Dilatation-Volvulus (GDV/Bloat)
Gastric dilatation-volvulus describes a sequence in which a dog's stomach fills with gas and then rotates on itself, trapping that gas and cutting off blood flow to the stomach wall and other organs. The rotation can happen rapidly, and the combination of pressure and compromised circulation affects the whole body. It occurs almost exclusively in dogs, particularly those with deep, narrow chests. Owners most often notice a swollen abdomen that feels tight or drum-like, along with unproductive retching: attempts to vomit that bring nothing up. The dog may seem restless, uncomfortable, or quieter than usual. Some dogs show drooling, pacing, or a hunched posture. The signs can appear suddenly, sometimes within hours of a meal or exercise, though the link is not always clear. This page explores what can be seen from the outside, what is happening inside the abdomen and circulation, how the condition is confirmed through imaging and examination, and the approaches used to address both the mechanical problem itself and the consequences that follow.
Why this matters now
GDV predominantly affects large and giant breed dogs, particularly those with deep, narrow chests such as Great Danes, German Shepherds, Standard Poodles, and Irish Setters. The condition can occur at any age but is more common in middle-aged to older dogs. Episodes often occur in the evening, sometimes following a meal or exercise.
GDV typically develops rapidly, progressing from initial stomach distension to a twisted stomach within hours or less. Once the stomach rotates, blood supply becomes compromised, and the condition escalates quickly. Without intervention, cardiovascular shock develops as blood return to the heart is impeded. The window for successful treatment narrows as the condition progresses. In a study of 166 dogs treated surgically, signs present for more than 6 hours before examination were associated with higher mortality and with more frequent need to remove dead stomach wall or the spleen. In a UK study of dogs seen at out-of-hours practices, about 79% of dogs that had surgery survived to discharge. Whether the stomach has only filled with gas or has also twisted, and whether its wall is still viable, cannot be judged from the outside; simple bloat and GDV look alike at home and are told apart on radiographs.
Signals & patterns
Early signals
Restlessness and inability to settle
Affected dogs often pace, change position frequently, and appear uncomfortable, unable to find a comfortable resting position.
Non-productive retching
Attempts to vomit that produce little or nothing are characteristic, as the twisted stomach prevents normal emptying.
Visible abdominal enlargement
The abdomen may appear distended or bloated, particularly on the left side behind the ribs. This develops progressively and can be slight early on, so a normal-looking abdomen does not rule out GDV in a dog that is retching without result.
Excessive drooling
Increased salivation often accompanies nausea and inability to vomit effectively.
Later signals
Rapid, shallow breathing
The enlarged stomach presses on the diaphragm and cardiovascular changes develop, affecting breathing.
Pale or grey gums
Poor circulation causes gum colour changes, indicating cardiovascular compromise.
Weakness or collapse
As shock develops, dogs become increasingly weak and may be unable to stand.
Rapid, weak pulse
Cardiovascular changes cause the heart rate to increase whilst pulse quality diminishes.
Click to read about the biological mechanisms
How this is usually investigated
GDV requires rapid assessment combining physical examination and imaging. The priority is stabilisation alongside diagnosis, as the dog's condition can change within hours.
Physical examination
Abdominal radiographs
Blood tests
Electrocardiogram
Options & trade-offs
GDV management combines stabilisation of the circulation with surgical correction. Various aspects of treatment address different components of the condition.
Gastric decompression
Releasing gas from the stomach via a tube through the mouth or needle through the body wall.
Trade-offs: Provides temporary relief of pressure whilst preparing for surgical correction. Does not address the underlying rotation.
Surgical correction
Returning the stomach to normal position and assessing tissue viability.
Trade-offs: Needed to correct the rotation in GDV. Allows direct assessment of stomach and spleen health. Non-viable tissue may require removal.
Gastropexy
Surgically attaching the stomach to the body wall to reduce the risk of future rotation.
Trade-offs: Greatly reduces the risk of the stomach twisting, whether done after an episode or preventively. Typically performed during corrective surgery. Some breeds may benefit from preventive gastropexy.
Intensive supportive care
Intravenous fluids, pain management, cardiac monitoring, and management of complications.
Trade-offs: Closely tied to survival. The postoperative period carries risks including cardiac arrhythmias and complications from tissue damage.
Common misconceptions
"Only very large dogs get bloat"
Whilst giant and large breeds are at highest risk, GDV can occur in medium-sized deep-chested dogs and occasionally in smaller breeds. A deep, narrow chest is a risk factor alongside size.
"Bloat always happens right after eating"
Whilst feeding may be a contributing factor, GDV can occur at any time. Episodes often happen in the evening but are not exclusively meal-related.
"A gastropexy completely prevents bloat"
Gastropexy greatly reduces the risk of the stomach twisting, the life-threatening volvulus component, but does not prevent simple bloat (dilatation without volvulus).
Related conditions
Foreign Body Ingestion
Foreign body ingestion may present with similar signs to early GDV: unproductive retching, abdominal discomfort, and restlessness, though the underlying cause differs. In some cases, a foreign object lodged in the stomach can contribute to gastric distension, though this is distinct from the rotation and circulatory collapse seen in GDV.
Gastric Ulceration
Gastric ulceration can develop as a consequence of GDV when blood flow to the stomach wall is compromised during the episode, or in the period following surgical correction while the damaged stomach wall is recovering. The combination of pressure, ischaemia, and inflammation creates an environment in which the protective lining may break down.
Congestive Heart Failure in Dogs
Congestive heart failure may be a consideration in older dogs presenting with abdominal distension and breathing difficulty, though the pattern of fluid accumulation and the absence of unproductive retching typically distinguish it from GDV.
Acute Pancreatitis
Acute pancreatitis can sometimes be confused with GDV in the early stages, as both may present with abdominal pain, vomiting or retching, and a hunched posture. The two conditions differ in mechanism, though distinguishing between them often requires imaging and clinical examination.
The page on this condition is being checked again and is offline for now.
Bloat Without Torsion
Bloat without torsion (simple gastric dilatation) is the gas-filled stage that can precede volvulus, and at home the two look the same: a distended abdomen, retching and restlessness occur in both. They are told apart on radiographs, and simple dilatation can progress to volvulus.
Splenic Mass
A bleeding splenic mass, most often haemangiosarcoma in older medium and large breed dogs, can cause a swollen abdomen, pale gums, weakness and collapse that overlap with later-stage GDV. Non-productive retching points more towards GDV, but internal bleeding and a twisted stomach are separated by examination and imaging.
Being familiar with the early signs allows faster recognition. In a large or deep-chested dog, repeated retching that brings nothing up, particularly alongside restlessness, drooling or a tight abdomen, is the pattern most associated with GDV. Abdominal swelling may be slight early on, so its absence does not rule the condition out, and no sign that can be checked at home shows whether the stomach has twisted. Time from the first signs to treatment is linked to survival, and a dog's condition can change substantially within a few hours. Preventive gastropexy is an option for some at-risk breeds, and whether it suits an individual dog depends on breed, age and general health.
Last reviewed: 9 October 2026 · Dr Alastair Greenway MRCVS