(Gastric Dilatation Volvulus)

Bloat is a life-threatening emergency that affects dogs in the prime of life. The mortality rate for gastric volvulus approaches about 50 percent. Early recognition and treatment are the keys to survival.

Anatomy of Bloat

Bloat actually refers to two conditions. The first is gastric dilatation, in which the stomach distends with gas and fliud. The second is volvulus, in which the distended stomach rotates on its long axis. The spleen is attached to the wall of the stomach, and therefore rotates with the stomach. Gastric dilatation may or may not be complicated by volvulus. If volvulus occurs the stomach may twist 180 degrees or less (technically called a torsion). An actual volvulus is a twist of a 180 degrees to 360 degrees or more. During volvulus, the pylorus is pulled out of position and becomes displaced to the left of the gastroesophageal junction. This pinches off the duodenum and prevents fliud and air from escaping from the stomach through the pyloric canal. Simultaneously, the gastroesophageal junction becomes twisted and obstructed, preventing the dog from belching and vomiting. Gas and fliud are trapped in the closed-off stomach, which becomes hugely distended as the material ferments. Interference with blood circulation results in necrosis of the wall of the stomach. This sequence produces a number of other problems, including acute dehydration, bacterial septicemia, circulatory shock, cardiac arrhythmias, gastric perforation, peritonitis and death. Bloat can occur in any dog at any age, but typically occurs in middle-aged to older dogs. There may be a familiar association. Large breed dogs with deep chest are anotomically predisposed. These breeds include the Great Dane, German Shepherd Dog, Saint Bernard, Labrador Retriever, Irish Wolfhound, Great Pyrenees, Boxer, Weimaraner, Old English Sheepdog, Irish Setter, Collie, Bloodhound and Standard Poodle. Chinese Shar-Pei and Basset Hounds have the highest incidence among mid-sized dogs. Small dogs are rarely affected, with the exception of Dachshunds, who are also deep-chested. Bloat develops suddenly, usually in a healthy, active dog. The dog may have just eaten a large meal, excercised vigorously before or after eating, or drank a large amount of water immediately after eating. There is no evidence that the protein or soy content in the diet contributes to bloat: research has shown that the majority of gas associated with bloat is due to swallowed air.

Signs of Bloat

The classic signs of bloat are restlessness and pacing, salivation, retching, unproductive attempts to vomit and enlargement of the abdomen. The dog may whine or groan when you press on his belly. Thumping the abdomen produces a hollow sound. Unfortunately, not all cases of bloat present with typical signs. In early bloat the dog may not appear distended, but the abdomen usually feels slightly tight. The dog appears lathargic, obviously uncomfortable, walks in a stiff legged fashion, hangs his head, but may not look extremely anxious or distressed. Early on, it is possible to distinguish dilatation from volvulus. Late signs (those of impending shock) include pale gums and tongue, delayed capillary refill time, rapid heart rate, weak pulse, rapid and labored breathing , weakness and collapse. If the dog is able to vomit or belch, quite likely the problem is not due to a volvulus, but this can only be determined by an examination.

Treating Bloat

In all cases where there is the slightest suspicion of bloat, take your dog to an animal hospital immediately. Time is of the essence. Gastric dilatation without torsion or volvulus is relieved by passing a long rubber or plastic tube through the dog's mouth into the stomach. This is also the quickest way to confirm a diagnosis of bloat. As the tube enters the dog's stomach, there should be a rush of air and fliud from the tube, bringing relief. The stomach is then washed out. The dog should not be allowed to eat or drink for at least 36 hours and will need to be supported with intravenous fliuds. If the symptoms do not return, the diet can be gradually restored. Passing a stomach tube is a procedure normally done by a trained professional (doggy doctor). In extreme circumstances when professional help is not available, you may be asked to perform the procedure at home. If you live in a remote location where fast access to animal services is limited, you may wish to aquire a stomach tube and add it to your home emergency medical kit. To pass a stomach tube , first mark the tube by measuring the distance from the dog's nose to his last rib Then lubricate the tube with K-Y or petroleum jelly. It is helpful to put a roll of adhesive tape in the dog's mouth to pass the tube through, so the dog cannot bite down on the tube. Insert the tube behind one of the canine teeth and advance it into the throat until the dog begins to swallow. If the dog gags, continue to advance the tube. If the dog coughs, the tube has entered the trachea. Withdraw the tube a few inches and start again. If the tube will not pass into the stomach, discontinue further attempts, as it is possible to harm the dog. If you do not have a tube available, a fairly large gauge sterile needle, such as an 18-gauge needle from a syringe may be used to poke directly through the body wall into the distended area to release gas and relieve pressure on the abdominal tissues. This is only a stopgap measure to buy you time to reach an animal hospital and only be done in a serious emergency in which there are no trained professionals available; because the needle could damage other tissue as it is pushed through the body wall. If you can pass a tube through, you should still take your dog to an animal hospital for follow-up treatment to prevent a recurrence. Being able to pass a tube through does not always rule out volvulus. Occasionally the tube passes even though the stomach is twisted. A diagnosis of dilatation or volvulus is best confirmed by X-rays of the abdomen. Dogs with simple dilatation have a large volume of gas in the stomach., but the gas pattern is normal. Dogs with volvulus have a "double bubble" gas pattern on the X-ray, with gas in two sections separated by the twisted tissue. Emergency therapy is directed toward correcting shock and dehydration with intravenous fluids and corticosteroids. Ventricular arrhythmias are common. They require heart monitoring and the use of anti-arrhythmic drugs. If a dog has a volvulus, emergency surgery is required as soon as the dog is able to tolerate the anesthesia. The goals are to reposition the stomach and spleen, or to remove the spleen and part of the stomach if these organs have undergone necrosis. Future recurrence can often be prevented by suturing the wall of the stomach to the abdominal wall a procedure called gastropexy. This important step keeps the stomach in position and prevents it from twisting.

Preventing Bloat

Dogs who respond to nonsurgical treatment have about a 70 percent chance of having another episode of bloat. Some of these episodes can be prevented by following these practices:

4 Divide the day's ration into three equal meals, spaced well apart.

4 Do not feed your dog from a raised food bowl.

4 Avoid feeding dry dog food.

4 Avoid foods that contain citric acid.

4 Restrict access to water one hour before and after meals.

4 Never let your dog drink a large amount of water all at once.

4 Avoid strenuous excercise on a full stomach.

4 Beware of the early signs and seek prompt professional help whenever you suspect bloat.