Genetic Welfare Problems of Companion Animals

Irish Setter

Gastric Dilatation-Volvulus Syndrome (GDV)

Related terms: bloat, gastric torsion

Outline: In gastric dilatation-volvulus syndrome, the stomach becomes massively distended with gas and fluid and may rotate around its axis, through 180 to 360 degrees, so that, among other complications, its blood supply is cut off. It is an intensely painful condition. Unless successfully treated it leads to death within hours. It is a common condition in Irish setters and it has been estimated that 24% develop the condition during their lifetime and 7% die of it. It appears to be a consequence of selecting for large size and a deep-chested conformation.

Summary of Information

(for more information click on the links below)

1. Brief description

Gastric dilatation-volvulus syndrome (GDV) is an extremely painful, life-threatening condition, in which the stomach rotates on its axis and becomes grossly distended by gas and fluid. The rotation may block blood supply to the stomach, and the blood flow back to the heart is compromised, with cardiogenic shock often following (Glickman et al 2000a, Brooks 2009, Tivers & Brockman 2009a). GDV tends to occur after a large meal or exercise (Tivers & Brockman 2009a). Affected dogs may appear depressed, restless or agitated and may show signs of pain, with an arched back and distended abdomen. There may also be retching, unproductive vomiting, and collapse (Tivers & Brockman 2009a, Fossum 2009).

The condition is prevalent in Irish setters and other, deep-chested, large or giant dogs (eg Great Danes, German Shepherd dogs, Gordon setters, Standard poodles, St Bernards, Weimaraners, Basset hounds and Doberman pinchers (Glickman et al 1994, Brooks 2009, Fossum 2009, Tivers & Brockman 2009a)). The risk of occurrence increases with age (Elwood 1998, Schellenberg et al 1998, Glickman et al 2000a,b) and is higher in dogs with a close relative (parent or sibling) which has had GDV (Burrows and Ignaszewski 1990, Schellenberg et al 1998, Glickman et al 2000b). The risk is also higher in thin dogs (Glickman et al 1997), in those which have a fearful/ anxious temperament (Glickman et al 1997) or which are stressed (Glickman et al 1997, Fossum 2009). The risk is greater following large meals (Glickman et al 1997, Elwood 1998, Brooks 2009, Tivers & Brockman 2009a), when dogs eat rapidly (Glickman et al 1997, 2000b, Tivers & Brockman 2009a) and when they are fed from raised feeding bowls (Glickman et al 2000b).

GDV is a medical emergency requiring immediate veterinary attention. Dogs with stomach rotation will die in great pain within a few hours without prompt treatment.

The prognosis for dogs with GDV depends upon how quickly they can be treated. Fossum (2009) reported 45% mortality, but mortality rate can be lower if treatment is prompt (Brockman et al 1995, Beck et al 2006, Rawlings et al 2002, Fossum 2009, Tivers & Brockman 2009a).

Prophylactic gastroplexy (preventive surgery to permanently attach the stomach to the abdominal wall) is often recommended for deep-chested dogs of large or giant breeds because of their high risk of GDV, especially if  they have had a parent or sibling with the condition (Rawlings et al 2002, Robbins 2008, Tivers & Brockman 2009b). This procedure is often performed at the same time as neutering.

2. Intensity of welfare impact   

GDV is an intensely painful condition. The stomach may become distended to many times its normal size (Brooks 2009).

Preventative surgery is likely to cause some discomfort.

3. Duration of welfare impact

Affected dogs die within hours unless successfully treated (Brooks 2009).

4. Number of animals affected

The Irish setter has consistently been overrepresented in surveys of this disease and has been shown to be significantly predisposed to the condition (Glickman et al 1994, Glickman et al 2000a, Tivers & Brockman 2009a, Evans & Adams 2010). Glickman et al (2000a) suggested that each Irish setter has a 24% chance of developing GDV during its lifetime. Between 5 and 7% of Irish setters die from GDV (Glickman et al 2000a, Evans & Adams 2010).

5. Diagnosis

Diagnosis is made on the basis of clinical examination and radiography (x-rays).

6. Genetics

GDV is typically a disease of breeds with a large body size and deep-chested conformation and it is likely, therefore, that various genes are involved (those that underlie this large size and conformation). The genes involved have not been determined.

High thoracic (chest) depth to width ratios (TDWRs) are significantly correlated with the risk of GDV in all breeds (Glickman et al 1996, Schellenberg et al 1998, Fossum 2009). The thoracic depth to width ratio is the ratio between the depth of the chest from spinal column to sternum and the width between the ribs from side to side. It can be measured from chest radiographs (x-rays).

It has been suggested that, in Irish setters, this conformation is due to an incomplete dominant major gene, influenced by other minor genes and environmental factors (Schaible et al 1997), but this has yet to be confirmed.

7. How do you know if an animal is a carrier or likely to become affected?

All Irish setters are at a relatively high risk of developing this condition during their lifetime and those with a parent or sibling that has been affected by GDV of a higher risk still (Burrows & Ignaszewski 1990, Schellenberg et al 1998, Glickman et al 2000b).

Dogs with a low chest depth to width ratio seem at lower risk of suffering from GDV (although we are not aware of any attempts to use this in practice to identify dogs for breeding that may be at lower risk).

8. Methods and prospects for elimination of the problem

It seems good advice, in the interests of tackling this problem, not to breed from dogs that have been affected or which have close relatives that have been affected. Since the disease is associated with large size and deep-chested conformation (Glickman et al 1996, Schaible et al 1997), selecting away from these characters may be advisable but as far as we know there are no data to support this.

Some may consider that perpetuating a breed in which a significant proportion of animals are likely to suffer extreme pain is not justifiable. Crossing with dogs of breeds in which the prevalence of GDV is low might help reduce prevalence.

For further details about this condition, please click on the following:
(these link to items down this page)

• Clinical and pathological effects
• Intensity of welfare impact
• Duration of welfare impact
• Number of animals affected
• Diagnosis
• Genetics
• How do you know if an animal is a carrier or likely to become affected?
• Methods and prospects for elimination of the problem
• Acknowledgements
• References

1. Clinical and pathological effects

Gastric dilatation-volvulus syndrome (GDV) is an extremely painful, life-threatening condition, in which the stomach rotates on its axis and becomes grossly distended by gas and fluid.

The stomach is a sac-like structure in the forward part of the abdomen just behind the diaphragm and liver. It is situated between the oesophagus, which conveys food from the mouth, and the small intestine. In large and giant breed dogs it may be positioned completely within the ribcage (Tivers & Brockman 2009a).

Where the stomach connects with the oesophagus and duodenum, there are sphincters – circular bands of muscle - which open and close to control the flow of contents in and out. At any time, the stomach normally contains varying amounts of food and gastric secretions including mucus, acid and enzymes. Rhythmic, periodic contractions thoroughly mix the stomach contents and propel them on into the small intestine. Normally only small amounts of gas are present in the stomach, which can be released up through the oesophagus as eructation (burping) or passed on through the lower sphincter into the intestines.

The cause of gastric dilatation-volvulus syndrome is not fully understood (Glickman et al 2000a, Tivers & Brockman 2009a). Anatomical, environmental, physiological and pathological factors are all thought to be involved (Tivers & Brockman 2009a). Brockman et al (2000) hypothesised two scenarios: (i) there is stomach rotation (volvulus) which then causes obstruction of the stomachs’ outflow or (ii) an obstruction of the gastric outflow occurs that, in turn, leads to dilatation of the stomach which then rotates. Fossum (2009) suggested that the primary cause may be a mechanical or functional outflow obstruction (ie scenario ii).

In GDV the stomach becomes distended with gas and fluid. In most dogs it rotates between 180° and 360° in a clockwise direction (Tivers & Brockman 2009a). In effect, it is much like the twisting of the casing used to separate out individual sausages from one another. In a small number of cases there is gastric dilatation without rotation. Brockman et al (1995) found this in 22% of cases. As a result of the distension, whether or not there is also rotation, gas and fluid in the stomach is unable to escape. The gas is thought to mainly be swallowed air (Fossum 2009, Tivers & Brockman 2009a) but may also be due to acid digestion of food. The fluid is from normal gastric fluid production and also caused by congestion of veins when the stomach becomes dilated (Fossum 2009). The stomach may become distended to many times its normal size (Brooks 2009).

In addition to completely obstructing outflow, stomach rotation also compromises the blood supply to the stomach wall which leads to ischaemia (starving of the tissues of blood and oxygen), and, if it persists, to death of the tissues and blood clot formation in the affected blood vessels. The spleen, which is closely attached to the stomach, can be displaced with associated tearing or obstruction of its blood supply (Tivers & Brockman 2009a).

The rotated, distended stomach also obstructs the vena cava and other large veins which convey blood from the abdominal organs and hindlegs back to the heart. The effects of this are multiple. First, the heart receives far less blood to pump to the lungs and the rest of the body. In response to this, heart rate increases and blood supply to less essential tissues and organs decreases. This is an emergency, physiological response, to save the life of the animal, however, in the longer term, its results can be life-threatening shock. The heart may fail due to decreased oxygenation as it works harder with a failing supply of oxygenated blood. This may lead to arrthythmias (irregular heartbeats) and cardiogenic shock, which further decreases output. This failing blood supply to the body causes tissue damage and the build up of toxic metabolites. (It is thought that the rapid release of these toxic substances into the general circulation if the blood supply to the stomach is corrected is partly responsible for the high mortality rates with GDV despite treatment. This is called ischaemic reperfusion injury (Tivers & Brockman 2009a).

In most dogs, GDV tends to occur after a large meal or exercise (Tivers & Brockman 2009a). Affected dogs may appear depressed, restless or agitated and may show signs of pain, with an arched back; and distended abdomen. There may be retching, unproductive vomiting, and collapse (Tivers & Brockman 2009a, Fossum 2009). GDV is a medical emergency requiring immediate veterinary attention. Dogs with stomach rotation will die in great pain within a few hours without prompt treatment.

There appears to be a number of risk factors for GDV (Tivers & Brockman 2009a) as listed below.

• Large or giant size (Burrows & Ignaszewski 1990, Evans & Adams 2010)
• Breed: Certain breeds, including Irish setters, are at increased risk (Glickman et al 1994; Tivers & Brockman 2009a; Fossum 2009; Evans and Adams 2010)
• High thoracic depth to width ratio ie a deep-chested conformation (Burrows & Ignaszewski 1990, Glickman et al 1996, Schaible et al 1997, Schellenberg et al 1998). Such a chest shape is thought to alter the relationship between the stomach and oesophagus, decreasing the ability to eructate (burp) (Guilford et al 1996).The thoracic depth to width ratio is the ratio between the depth of the chest from spinal column to sternum and the width between the ribs from side to side. It can be measured from chest radiographs (x-rays).

A high thoracic depth to width ratio is highly correlated with risk of GDV (Fossum 2009). Schellenberg et al (1998) found Irish setters with the greatest ratio to be significantly more likely to develop GDV than those with the lowest ratios. Glickman et al (1996) suggested that 37% of the variability in risk of GDV was associated with this ratio. The ratio (chest shape) seems to be inherited (Schaible et al 1997).

• Increasing age (Elwood 1998, Schellenberg et al 1998, Glickman et al 2000a, b). It has been suggested that the ligaments that support the stomach stretch as life progresses which makes rotation more likely in older animals (Hall et al 1995). However, dogs from as young as a few months old can develop GDV (Muir 1982; Schellenberg et al 1998). Glickman et al (2000a) found that in the Irish setter and dogs of other large breeds, risk increased throughout life from three years of age.
• Having a first degree relative (parent or sibling) which has had GDV (Burrows & Ignaszewski 1990, Schellenberg et al 1998, Glickman et al 2000b).
• Thin body condition (Glickman et al 1997)
• A fearful/anxious temperament (Glickman et al 1997)
• Stress (Glickman et al 1997, Fossum 2009)

Various studies have looked at the role of diet in GVD but this remains unclear. However, most authors agree that the following environmental factors influence risk.

• The feeding of large meals (Glickman et al 1997, Elwood 1998, Brooks 2009, Tivers and Brockman 2009a)
• Rapid eating (Glickman et al 1997, 2000b, Tivers and Brockman 2009a)
• Feeding from a raised feeding bowl (Glickman et al 2000b)

Emergency treatment of GDV involves decompression of the stomach, rapid treatment of shock, and assessment for the presence of gastric rotation, usually using radiography. If stomach rotation has occurred then surgical correction is required, along with medical and surgical treatment of any secondary effects of GDV, such as heart arrhythmias and splenic torsion. All dogs that have had GDV should have a surgical gastroplexy to permanently anchor the stomach to the abdominal wall to prevent reoccurrence. If gastroplexy is not performed at this time then reoccurrence rates of up to 80% are reported (Fossum 2009, Tivers & Brockman 2009b).

Without treatment, the disease is rapidly fatal. The prognosis for treated dogs depends upon how quickly they are treated. Fossum (2009) reported 45% mortality, but mortality rates can be significantly lower if treatment is prompt (Brockman et al 1995, Beck et al 2006, Rawlings et al 2002, Fossum 2009, Tivers & Brockman 2009b).

The prognosis where there is stomach dilatation without twisting is better than in cases where there is twisting (Rawlings et al 2002, Fossum 2009, Tivers & Brockman 2009b).

Occasionally cases of more chronic disease, with only partial gastric outflow obstruction and stomach distension, are seen (Tivers & Brockman 2009a).

Many authors recommend prophylactic gastroplexy to prevent GDV in dogs which are at high risk such as those with an affected parent or sibling (Glickman et al 2000b, Rawlings et al 2002, Robbins 2008, Tivers and Brockman 2009b).

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2. Intensity of welfare impact

GDV is an intensely painful condition which, if untreated, leads to death within a few hours. Even with treatment many dogs have their lives shortened by this condition and some may need removal of sections of the stomach which may have long term consequences to stomach function.

The pain of this condition is extreme – described as “tremendous abdominal pain” by Brooks (2009). The stomach may become distended to many times its normal size (Brooks 2009).

Necessary medical and surgical treatments can cause further distress for these animals.

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3. Duration of welfare impact

Dogs with GDV die within hours unless successfully treated. 

Occasionally cases of more chronic disease, with only partial gastric outflow obstruction and stomach distension, are seen (Tivers & Brockman 2009a).

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4. Number of animals affected

The Irish setter has been found to be consistently overrepresented in surveys of GDV (Glickman et al 2000a, Tivers & Brockman 2009a, Evans & Adams 2010).

In a recent UK study, 5.3% of Irish setter deaths were found to be due to GDV (Evans & Adams 2010). These authors found that Irish setters were 2.3 times more likely to die and 10 times more likely to suffer from this disease than the average purebred dog. Glickman et al (2000a) found 20 out of 248 Irish setters monitored for just under 3 years developed GDV, that is, 2.4 % of the Irish setters studied developed GDV each year. Glickman et al (2000a) suggested that Irish setters have a 24% chance of developing the condition during their lifetime (assuming a 10 year life-span) and a 7% chance of dying from it (given a 30% mortality rate).

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5. Diagnosis

GDV may be suspected in any Irish setter showing the typical signs and can be confirmed by radiography. Other diagnostic and therapeutic procedures may then follow to aid treatment.

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6. Genetics

GDV is typically a disease of breeds with a large body size and deep-chested conformation and it is likely, therefore, that various genes are involved (including those that underlie large size). The genes involved have not been determined.

High thoracic (chest) depth to width ratios (TDWRs) are significantly correlated with the risk of GDV in all breeds (Glickman et al 1996, Schellenberg et al 1998, Fossum 2009). The thoracic depth to width ratio is the ratio between the depth of the chest from spinal column to sternum and the width between the ribs from side to side. It can be measured from chest radiographs (x-rays).

It has been suggested that, in Irish setters, this conformation is due to an incomplete dominant major gene, influenced by other minor genes and environmental factors (Schaible et al 1997), but this has yet to be confirmed.

Return to top

7. How do you know if an animal is a carrier or likely to become affected?

All Irish setters are at a relatively high risk of developing this condition during their lifetime and those with a parent or sibling that has been affected by GDV are at higher risk still (Burrows & Ignaszewski 1990, Schellenberg et al 1998, Glickman et al 2000b).

Dogs with a low chest depth to width ratio seem at lower risk of suffering from GDV (although we are not aware of any attempts to use this in practice to identify dogs for breeding that may be at lower risk). Those with a parent or sibling that has been affected by GDV are at increased risk (Burrows & Ignaszewski 1990, Schellenberg et al 1998, Glickman et al 2000b).

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8. Methods and prospects for elimination of the problem

It seems good advice, in the interests of tackling this problem, not to breed from dogs that have been affected or which have close relatives that have been affected. Glickman et al (2000b) suggested that if this could be implemented, then there could be a 60% decrease in prevalence (but one difficulty is that dogs may often reach breeding age long before they suffer GDV).

Since the disease is associated with large size and deep-chested conformation (Glickman et al 1996, Schaible et al 1997), selecting away from these characters may be advisable but as far as we know there are no data to support this.

Currently there do not seem to be any breeding schemes aimed at decreasing the prevalence of GDV in Irish setters.

Some may consider that perpetuating a breed in which such a significant proportion of animals are likely to suffer extreme pain is not justifiable. Crossing with dogs of breeds in which the prevalence of GDV is low might help reduce prevalence.

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9. Acknowledgements

UFAW is grateful to Rosie Godfrey BVetMed MRCVS and David Godfrey BVetMed FRCVS for their work in compiling this section.

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10. References

Beck JJ, Staatz AJ, Pelsue DH, Kudnig ST, MacPhail CM, Seim HB and Monnet E (2006) 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 229: 1934-1939

Brockman DJ, Washabau RJ and Drobatz KJ (1995) Canine gastric dilatation/volvulus syndrome in a veterinary critical care unit: 295 cases (1986-1992). Journal of American Veterinary Medical Association 207: 460-4

Brockman DJ, Holt DE and Washabau RJ (2000) Pathogenesis of acute canine gastric dilatation–volvulus syndrome: is there a unifying hypothesis? Compendium on Continuing Education for the Practicing Veterinarian 22: 1108-1113

Brooks W (2009) Bloat - The Mother of All Emergencies. On-line client information sheet http://www.VeterinaryPartner.com/Content.plx?P=A&A=672. Accessed 14.3.11

Burrows CF and Ignaszewski LA (1990) Canine gastric dilatation-volvulus. Journal of Small Animal Practice 31: 495–501

Elwood CM (1998) Risk factors for gastric dilatation in Irish setter dogs Journal of Small Animal Practice 39: 185-190

Evans KM and Adams VJ (2010) Mortality and morbidity due to gastric dilatation-volvulus syndrome in pedigree dogs in the UK. Journal of Small Animal Practice 51: 376-381

Fossum T (2009) Gastric Dilatation Volvulus: What's New? World Small Animal Veterinary Association congress proceedings 21-24 July Sao Paulo, Brazil. http://www.vin.com/Members/Proceedings/Proceedings.plx?CID=wsava2009&PID=pr53584&O=VIN Accessed 14.2.11

Glickman LT, Glickman NW, Pérez CM, Schellenberg DB and Lantz GC (1994) Analysis of risk factors for gastric dilatation and dilatation-volvulus in dogs. Journal of American Veterinary Medical Association 204: 1465-71

Glickman LT, Emerick T, Glickman NW, Glickman S, Lantz GC, Pérez CM, Schellenberg DB, Widmer W and Ti Q (1996) Radiological assessment of the relationship between thoracic conformation and the risk of gastric dilatation-volvulus in dogs Veterinary Radiology & Ultrasound 37: 174-180

Glickman LT, Glickman NW, Schellenberg DB, Simpson K and Lantz GC (1997) Multiple risk factors for the gastric dilatation-volvulus syndrome in dogs: a practitioner/owner case-control study. Journal of the American Animal Hospital Association 33: 197-204

Glickman LT, Glickman NW, Schellenberg DB, Raghavan M and Lee TL (2000a) Incidence of and breed-related risk factors for gastric dilatation-volvulus in dogs. Journal of the American Veterinary Medical Association 216: 40-45

Glickman LT, Glickman NW, Schellenberg DB, Raghavan M and Lee TL (2000b) Non dietary risk factors for gastric dilatation-volvulus in large and giant breed dogs. Journal of American Veterinary Medical Association 217: 1492-1499

Guilford WG, Center SA, Strombeck DR, Williams DA and Meyer DJ (1996) Gastric dilatation, gastric dilatation-volvulus, and chronic gastric volvulus. In: Strombeck DR (ed) Small Animal Gastroenterology 3rd edition. Philadelphia: WB Saunders pp304–306

Hall JA, Willer RL, Seim HB and Powers BE (1995) Gross and histologic evaluation of hepatogastric ligaments in clinically normal dogs and dogs with gastric dilatation-volvulus. American Journal of Veterinary Research 56: 1611-1614

Muir WW (1982) Gastric dilatation-volvulus in the dog, with emphasis on cardiac arrhythmias. Journal of American Veterinary Medical Association 180: 739-42

Rawlings C, Mahaffey M, Bement S and Canalis C (2002) Prospective evaluation of laparoscopic-assisted gastropexy in dogs susceptible to gastric dilatation. Journal of the American Veterinary Medical Association 221: 1576-1581

Robbins M (2008) Gastric Dilatation/ volvulus syndrome in dogs. On-line http://www.acvs.org/AnimalOwners/HealthConditions/SmallAnimalTopics/GastricDilatationVolvulus/. Accessed 16.3.11

Schaible RH, Ziech J, Glickman NW, Schellenberg D, Yi Q and Glickman LT (1997) Predisposition to gastric dilatation-volvulus in relation to genetics of thoracic conformation in Irish setters. Journal of American Animal Hospital Association 33: 379-83

Schellenberg D, Yi Q, Glickman NW and Glickman LT (1998) Influence of thoracic conformation and genetics on the risk of gastric dilatation-volvulus in Irish setters. Journal of American Animal Hospital Association 34: 64-73

Tivers M and Brockman DJ (2009a) Gastric dilatation-volvulus syndrome in dogs 1. Pathophysiology, diagnosis and stabilisation. In Practice 31: 66-69

Tivers M and Brockman DJ (2009b) Gastric dilatation-volvulus syndrome in dogs 2. Surgical and Postoperative Management. In Practice 31: 114

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