Changes

==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 in a clockwise direction from its normal position to a dorsal, cranial and leftward location. 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.

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 in a clockwise direction through an angle of between 180 and 360^o from its normal position to a dorsal, cranial and leftward location. 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.

==Risk factors==

==Risk factors==

==History and Clinical signs==

==History and Clinical signs==

The onset of the characteristic clinical signs of abdominal distension and unproductive vomiting is usually acute. The clinical signs are often reported to follow a period of exercise and/or feeding of a large meal.  

The clinical signs of GDV are usually acute in onset and may follow a periood of exercise and/or feeding of a large meal. Affected dogs typically display non-productive vomiting and abdominal distension. 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. Abdominal tympany is often displayed and the animal may be painful.

On physical examination, the dog may be collapsed or reluctant to stand. Abdominal distension and tympany are often  

 

==Diagnosis==  

==Diagnosis==