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Commonly affected breeds include German Shepherds, Great Danes, Irish Wolfhounds, St Bernards and Doberman Pinschers. GDV has also been reported to occur in cats, primates and rarely small breed dogs such as Dachshunds and Miniature Poodles.

Commonly affected breeds include German Shepherds, Great Danes, Irish Wolfhounds, St Bernards and Doberman Pinschers. GDV has also been reported to occur in cats, primates and rarely small breed dogs such as Dachshunds and Miniature Poodles.

==Risk factors==

==Risk Factors==

The exact aetiology of the condition is unknown but a number of risk factors have been identified. Studies have shown that dogs with a '''reduced thoracic width to depth ratio''' are at an increased risk of developing GDV. Female dogs are also more likely to develop GDV than males and stressed, anxious dogs are more likely to develop GDV than calm dogs. Other risk factors include obesity, feeding a dry food diet and exercise after feeding.  

The exact aetiology of the condition is unknown but a number of risk factors have been identified. Studies have shown that dogs with a '''reduced thoracic width to depth ratio''' are at an increased risk of developing GDV. Female dogs are also more likely to develop GDV than males and stressed, anxious dogs are more likely to develop GDV than calm dogs. Other risk factors include obesity, feeding a dry food diet and exercise after feeding.  

==Pathogenesis==   

==Pathogenesis==   

An obstruction to gastric emptying due to fluid or gas leads to '''gastric distention''' and a rapid increase in intra-gastric pressure. As the stomach dilates, the '''pylorus shifts through an angle of between 180 and 360^o''' from its normal position to a dorsal, cranial and leftward location. More than 90% of all gastric volvuli rotate in a '''clockwise direction''' when viewed from the surgeon's perspective with the dog in dorsal recumbency.

An obstruction to gastric emptying due to fluid or gas leads to '''gastric distention''' and a rapid increase in intra-gastric pressure. As the stomach dilates, the '''pylorus shifts through an angle of between 180 and 360^oC''' from its normal position to a dorsal, cranial and leftward location. More than 90% of all gastric volvuli rotate in a '''clockwise direction''' when viewed from the surgeon's perspective with the dog in dorsal recumbency.

The most immediate effect is impairment of the gastric blood supply, leading to severe congestion of the gastric wall and infarction and ulceration of the gastric mucosa. Venous return to heart is reduced due to mechanical compression of the caudal vena cava by the distended stomach, leading to decreased cardiac output and hypovolaemic shock. Gastric distension also causes a mechanical impediment to movement of the diaphragm resulting in reduced tidal volume, hypoxia and hypercapnia.

The most immediate effect is impairment of the gastric blood supply, leading to severe congestion of the gastric wall and infarction and ulceration of the gastric mucosa. Venous return to heart is reduced due to mechanical compression of the caudal vena cava by the distended stomach, leading to decreased cardiac output and hypovolaemic [[shock]]. Gastric distension also causes a mechanical impediment to movement of the diaphragm resulting in reduced tidal volume, hypoxia and hypercapnia.

In addition to the above systemic effects, displacement of the stomach may lead to avulsion of the gastric branches of the splenic artery. Significant haemorrhage may occur as a result and this may lead to the development of ischaemia-induced gastric necrosis.  

In addition to the above systemic effects, displacement of the stomach may lead to avulsion of the gastric branches of the splenic artery. Significant haemorrhage may occur as a result and this may lead to the development of ischaemia-induced gastric necrosis.  

==History and Clinical signs==

==History and Clinical Signs==

The clinical signs of GDV are usually '''acute in onset''' and may follow a period of exercise and/or feeding of a large meal. Affected dogs typically display '''non-productive vomiting and abdominal distension'''. Acute onset restlessness, abdominal pain, hypersalivation and abdominal tympany are other common features of GDV. On physical examination, the dog may be collapsed or reluctant to stand. Signs of cardiovascular '''shock''' may be present including tachycardia, pale mucous membranes, prolonged capillary refill time and poor peripheral pulses. An irregular heart rate combined with pulse deficits indicates the presence of cardiac arrhythmias.

The clinical signs of GDV are usually '''acute in onset''' and may follow a period of exercise and/or feeding of a large meal. Affected dogs typically display '''non-productive vomiting and abdominal distension'''. Acute onset restlessness, abdominal pain, hypersalivation and abdominal tympany are other common features of GDV. On physical examination, the dog may be collapsed or reluctant to stand. Signs of cardiovascular '''shock''' may be present including tachycardia, pale mucous membranes, prolonged capillary refill time and poor peripheral pulses. An irregular heart rate combined with pulse deficits indicates the presence of [[Arrhythmia|cardiac arrhythmias]].

==Diagnosis and Management==

==Diagnosis and Management==

Diagnosis is usually based on the '''patient's signalment and a history of unproductive vomiting and abdominal distension'''.  

Diagnosis is usually based on the '''patient's signalment and a history of unproductive vomiting and abdominal distension'''.  

Initial emergency treatment should be aimed at managing the dog's '''hypovolaemic shock'''. It may be beneficial to provide oxygen supplementation whilst the dog is being stabilised.  

Initial emergency treatment should be aimed at managing the dog's '''hypovolaemic shock'''. It may be beneficial to provide oxygen supplementation whilst the dog is being stabilised.  

Large bore (16 or 18 gauge) catheters should be placed into the cephalic or jugular veins and a proportion of the '''shock dose of Compound Sodium Lactate''' (90ml/kg/h) should be administered intravenously based on the severity of the dog's clinical signs. Hypertonic saline or colloid fluids may be indicated in very large dogs or those who have not responded to a bolus dose of crystalloid fluids.  

Large bore (16 or 18 gauge) catheters should be placed into the cephalic or jugular veins and a proportion of the '''shock dose of Compound Sodium Lactate''' (90ml/kg/h) should be administered intravenously based on the severity of the dog's clinical signs. Hypertonic saline or colloid fluids may be indicated in very large dogs or those who have not responded to a bolus dose of crystalloid fluids.  

===Gastric decompression===

===Gastric Decompression===

Following a period of aggressive fluid therapy, '''gastric decompression''' should be performed. A lubricated large-bore stomach tube is premeasured (from nostril to last rib) and marked. A roll of 2 inch adhesive tape should be inserted behind the canine teeth and the dog's mouth should be held closed around the banadage. The stomach tube can then be introduced through the bandage into the oesophagus. It is important to mimimise stress when this procedure is carried out. Sedation is not usually required but suitable drugs for this include Butorphanol, Fentanyl or Diazepam. If the animal is resistant to orogastric intubation or becomes stressed, '''trocharization''' of the most tympanic area caudal to the ribs with a 14 to 16 gauge catheter may be performed. This may allow subsequent completion of orogastric intubation for further. Temporary '''gastrostomy''' may also be considered.

Following a period of aggressive fluid therapy, '''gastric decompression''' should be performed. A lubricated large-bore stomach tube is premeasured (from nostril to last rib) and marked. A roll of 2 inch adhesive tape should be inserted behind the canine teeth and the dog's mouth should be held closed around the bandage. The stomach tube can then be introduced through the bandage into the oesophagus. It is important to minimise stress when this procedure is carried out. Sedation is not usually required but suitable drugs for this include Butorphanol, Fentanyl or Diazepam. If the animal is resistant to orogastric intubation or becomes stressed, '''trocharization''' of the most tympanic area caudal to the ribs with a 14 to 16 gauge catheter may be performed. This may allow subsequent completion of orogastric intubation for further decompression. Temporary '''gastrostomy''' may also be considered.

===Radiography===

===Radiography===

'''Abdominal radiography''' may be beneficial in confirming a diagnosis of GDV and distinguishing between GDV and gastric dilatation. Radiography should not be carried out until gastric decompression has been performed and intravenous fluids have been started. A radiograph performed in right lateral recumbency shows a dorso-cranially positioned pylorus to the left of the midline. The stomach will appear compartmentalised (the classic ''''double bubble'''' pattern) with a soft tissue strip separating the two compartments. The oesophagus may appear dilated with air or fluid. Evidence of air in the abdomen indicates that perforation has occurred and requires an exploratory surgical procedure. Loss of contrast in the abdomen may indicate peritonitis or haemoabdomen.

'''Abdominal radiography''' may be beneficial in confirming a diagnosis of GDV and distinguishing between GDV and gastric dilatation. Radiography should not be carried out until gastric decompression has been performed and intravenous fluids have been started. A radiograph performed in right lateral recumbency shows a dorso-cranially positioned pylorus to the left of the midline. The stomach will appear compartmentalised (the classic ''''double bubble'''' pattern) with a soft tissue strip separating the two compartments. The oesophagus may appear dilated with air or fluid. Evidence of air in the abdomen indicates that perforation has occurred and requires an exploratory surgical procedure. Loss of contrast in the abdomen may indicate [[peritonitis]] or haemoabdomen.

===Other diagnostic tools===

===Other Diagnostic Tools===

Plasma '''lactate''' concentration has been reported to have a strong link with the patient's prognosis due its association with gastric necrosis and systemic hypovolaemia. A plasma lactate greater than 6 mmol/L is associated with a poor prognosis.  

Plasma '''lactate''' concentration has been reported to have a strong link with the patient's prognosis due to its association with gastric necrosis and systemic hypovolaemia. A plasma lactate greater than 6 mmol/L is associated with a poor prognosis.  

'''Electrocardiography''' (ECG) is essential as cardiac arrhythmias may occur in up to 40% of dogs with GDV. Most arrhythmias are ventricular in origin and occur within 36 hours of admission. Ventricular tachycardia is the most common rhythm disturbance displayed but many other arrhythmias may occur.

'''Electrocardiography''' (ECG) is essential as cardiac arrhythmias may occur in up to 40% of dogs with GDV. Most arrhythmias are ventricular in origin and occur within 36 hours of admission. [[Ventricular Tachycardia|Ventricular tachycardia]] is the most common rhythm disturbance displayed but many other arrhythmias may occur.

==Treatment==

==Treatment==

The abdomen should be '''lavaged''' prior to closure.

The abdomen should be '''lavaged''' prior to closure.

==Post-operative complications and care==

==Post-operative Complications and Care==

The most common complications following GDV surgery include '''cardiac arrhythmias, shock, hypokalaemia and surgical complications such as dehiscence'''. Ventricular tachycardia is the most common abnormal rhythm and continuous ECG monitoring is recommended for the 24-48 hours following surgery. Intravenous fluid therapy should be continued and the haemodynamic, acid-base and electrolyte balance should also be closely monitored. If vomiting occurs the patient should be evaluated for possible peritonitis and if gastric rupture.  

The most common complications following GDV surgery include '''cardiac arrhythmias, shock, [[hypokalaemia]] and surgical complications such as dehiscence'''. Ventricular tachycardia is the most common abnormal rhythm and continuous ECG monitoring is recommended for the 24-48 hours following surgery. Intravenous fluid therapy should be continued and the haemodynamic, acid-base and electrolyte balance should also be closely monitored. If vomiting occurs the patient should be evaluated for possible peritonitis and if gastric rupture.  

==Prognosis==

==Prognosis==

{{Learning

{{Learning

|flashcards = [[Small Animal Soft Tissue Surgery Q&A 02]]<br>[[Small Animal Emergency and Critical Care Medicine Q&A 09]]}}

|flashcards = [[Small Animal Soft Tissue Surgery Q&A 02]]<br>[[Small Animal Emergency and Critical Care Medicine Q&A 09]]}}

 

|literature search = [http://www.cabdirect.org/search.html?q=((title:(GDV)+AND+od:(dogs)))+OR+((title:(gastric)+AND+title:(dilat*)+AND+title:(volvulus)))  Gastric Dilatation and Volvulus publications]

==Literature Search==

 

 

[http://www.cabdirect.org/search.html?q=((title:(GDV)+AND+od:(dogs)))+OR+((title:(gastric)+AND+title:(dilat*)+AND+title:(volvulus)))  Gastric Dilatation and Volvulus publications]

==References==

==References==

[[Category:Stomach_and_Abomasum_-_Pathology]][[Category:Gastric Diseases - Dog]]

[[Category:Stomach_and_Abomasum_-_Pathology]][[Category:Gastric Diseases - Dog]]

[[Category:Expert_Review - Small Animal]]

[[Category:Expert_Review - Small Animal]]