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 fashion from its normal position to a dorsal, cranial and leftward location.The most immediate effect is impairment of the gastric blood supply. The gastric wall becomes severely congested and infarction and ulceration of the gastric mucosa may occur. Venous return to heart is reduced due to mechanical compression of the caudal vena cava by the distended stomach. This compresses the diaphragm and interferes with respiration.

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.

==Risk factors==

==Risk factors==