What is GDV?

GDV ( Gastric Dilatation & Volvulus ) is a critical emergent medical case of a severe dilation and torsion of the stomach in a dog. It usually happens on large breed and deep chest dogs but could sometimes happen on small breed dogs. Dogs usually develop to GDV within couple of hours. The chance of survival is zero if it is not treated immediately.

Pathophysiology of GDV

Initially, the fundus of the stomach starts distending. The muscle layer of pylorus is thicker and stiffer so it is less distensible compared to the fundus; therefore, the pylorus will be pushed away by the distended fundus. The more the dog gets nervous and pants due to the discomfort and pain, the more the gas enters into the stomach. When the fundus is continuing to distend, the fundus will give a push to the pylorus downward at the right side of the abdominal cavity; therefore, the pylorus will go around the bottom of the fundus and reach to the bottom left of the abdominal cavity. When the fundus is further distended, the pylorus has no way to go but is squeezed upward to the top left. At this position, the duodenum meets and crosses around the esophagus. This configuration traps all the gas and ingesta into the stomach, and the gas and ingesta are neither passed down to the small intestines nor vomited out. The aorta and vein are compressed causing a poor circulation. The lesser the blood supply to the stomach, the higher the chance it gets necrosis. Splenic torsion or rupture may occur concurrently when the fundus of the stomach distended sufficiently.  Haemorrhage from the gastric and splenic vessels is very common due to the strong traction force produced by the fundus distension and torsion. Over a short period, the patient will die in hypovolemia and hypoxemia due to the poor circulation and insufficient cardiac output.

Cause of GDV

The cause of GDV is unknown. The risk of GDV seems related to the thoracic confirmation. The deeper thorax is more likely to experience GDV. There is still debating what predisposes dogs to GDV. However, any issue that causes abnormal gastric motility such as gastric foreign body and mass may predispose to GDV.

(** My personal opinion: the abdominal wall angle predisposes to GDV in large breed dogs and deep chested dogs. The angle of abdominal wall of deep chest dogs is higher of which pylorus will be pushed from right to left and forward when the fundus is distended. When the fundus is further distended, the pylorus will be left up on the left side. )

Symptoms of GDV

Initially, dogs with GDV will have frequent vomiting over a short period. Some dogs may develop unproductive retching and salivation. Panting follows and abdominal starts to distend. Later, the abdomen is distended and noticeable. Panting and unproductive retching continue. Finally, the dogs will collapse or be in coma and die.

There are many complications of GDV including endotoxiemia, septic shock, haemorrahge, splenic rupture, intestinal necrosis and stomach necrosis etc.

Diagnosis of GDV

Radiograph of abdominal cavity can be used to confirm the stomach distension and torsion. Blood tests are usually performed to obtain information for anaesthesia and initial therapy.

Treatment of GDV

There is no chance for a dog to recover from GDV on itself. This is always an emergent case, and requires surgery to treat it.

Veterinarians will perform a set of emergency procedures including an aggressive high rate intravenous fluid therapy and decompression of the stomach to try to stabilize the dog as much as possible. The aggressive intravenous fluid can expand the blood volume and aid better circulation. Decompression of stomach will relieve the pressure of the stomach thus aid the circulation. Other treatments include antibiotics and analgesia. When blood pressure increases to a better level, anaesthesia and surgery are able to start. Veterinary Surgeon will decompress the stomach and reposition the stomach. Control the bleeding and remove any necrotic parts of the stomach or intestines. Sometimes the spleen will be removed if the splenic vessels are severely damaged. At the end, veterinary surgeon will suture the pylorus of the stomach to the right side of the abdominal wall to prevent recurrence of GDV.

Advice

Calm down and call up your veterinarian immediately when you suspect your dog has GDV!