As the stomach begins to swell it also rotates closing both the inlet and outlet which prevents any gas or fluid escaping. Further swelling and rotation occur as gas from the fermenting stomach contents, and gastric juices are excreted into the stomach. The time taken for this condition to reach a critical stage can be as little as 30 minutes. Most of the damage to the body is due to changes in blood flow to organs as the swollen stomach crushes major blood vessels including the caudal vena cava and portal veins. The abdominal organs including the liver are effected leading to a build up of toxins which can trigger toxic shock. The spleen is particularly effected by GDVT as it is dragged around by the rotating stomach twisting and occluding the splenic blood vessels. Pressure on the vena cava slows blood flow back to the heart greatly effecting the circulation to the point of causing hypovolemic shock (not enough blood circulating). The enlarged stomach pushes on the diaphragm making breathing difficult and painful. Lung capacity is reduced so the amount of oxygen entering the blood lowers further compromising the situation created by poor blood flow in the body.

In the early stages of GDVT the swelling of the stomach may not be apparent. The dog will look uncomfortable and try to vomit without producing any stomach contents. As the distention increases the swelling will become more obvious especially on the left side of the abdomen. Breathing becomes labored and there may be constant salivation (drooling). This condition is an emergency

GVDT is treated by rapid intravenous fluids (drip) to correct shock. The stomach is slowly decompressed using a large needle placed in through the abdominal wall. A tube is passed down the esophagus into the stomach once the pressure has been reduced and the contents is emptied. If a torsion (rotation) is present the tube may be unable to enter the stomach. These animals require surgery to correct the position of the stomach which is then anchored to the wall of the abdomen (gastropexy) to help prevent further episodes.

Unfortunately not all dogs suffering GDVT will survive despite treatment. Shock and toxemia may result in death before treatment can be completed. After treatment heart failure can occur secondary to the release compounds within the body which alter the rhythm of the heart. \

Prevention of GDVT may be improved by feeding smaller meals several times per day in preference to one large meal. All food should be moistened. Water intake and exercise should be restricted around the time of eating.