In human beings, bloating may sound like a fairly mild problem, brought on by a too-large meal or perhaps water retention.
In dogs, however, bloat is only one name for a life-threatening condition that's also known as gastric dilation-volvulus (GDV), stomach torsion or twisted stomach. Affected dogs will die within several hours if left untreated, and even with treatment more than a quarter of dogs with GDV die.
Bloat is a two-fold illness with several causes. First, for a variety of reasons, the stomach can fill up with air, putting pressure on nearby internal organs, on the large veins in the abdomen and the diaphragm. This in turn makes it difficult for the dog to breathe and prevents blood from returning to the heart.
Once it's filled with air, the stomach will sometimes rotate on its own axis, cutting off its blood supply. Once this occurs, the stomach begins to die very rapidly. Since the dog's blood supply is disrupted, the dog's overall condition also begins to go downhill very rapidly.
Purebred dogs are much more susceptible to GVD than mixed breeds, and the condition occurs much more often in large dogs with deep, narrow chests. Breeds that can be prone are: Gordon Setters, Great Danes, Irish Setters, Saint Bernards, Standard Poodles and Weimaraners. Bloat usually appears in animals that are over seven years old; it's rare in younger animals, especially those under age four. Also, male dogs are more than twice as likely to develop GDV as females; regardless of whether or not the animal has been neutered.
Owners can take precautions to help their dog avoid bloat. Start by feeding the dog two meals a day or leaving a bowl of food out, so the animal can "graze" throughout the day. Dogs that eat only one large meal a day are much more likely to develop GDV, especially if they gulp their food. Also, don't allow your dog to run around or exercise vigorously right after a large meal; this is the type of activity that often leads to the stomach becoming twisted. For reasons that aren't yet understood, dogs that have a nervous or fearful temperament also are at a higher risk.
When a dog is experiencing bloat, owners usually notice that its abdomen is swollen and it appears to be vomiting, yet nothing is coming up. In addition, symptoms include abdominal pain, restlessness, drooling and rapid shallow breathing. If the stomach has twisted, before long the animal may go into shock. Dogs in shock will become pale, have a weak pulse and a rapid heart rate, and will eventually collapse.
Dogs with GVD will be treated with intravenous fluids to ward off shock, followed by removing the pent-up gas from the stomach, through either a stomach tube down the throat or a needle inserted into the stomach. Various types of medications, including antibiotics, blood thinners (to prevent clots) and pain medications also may be administered to help stabilize the animal's condition. Once stabilized, surgery is performed. In some cases, the stomach can be surgically restored to its proper position. In other cases, however, the stomach and/or spleen may be so damaged that the animal must be euthanized. As part of the surgery, the veterinary surgeon must perform a gastropexy, a procedure that stitches the stomach in place in order to prevent it from twisting again. If this step is not taken, nearly 80 percent of affected dogs will experience a recurrence.