| Clinical Name: Gastric Dilatation and Volvulus (GDV) Overview Any dog that shows signs of bloat, a serious and potentially fatal illness,should receive emergency veterinary medical care immediately. Clinically known as gastric dilation, bloat occurs when a dog's stomach becomes so swollen with gas that it is unable to relieve the pressure. As the stomach becomes distended, it often rotates on its axis. This volvulus, or twisting, cuts off blood flow to the stomach and often the spleen as well, and is thus clinically known as gastric dilatation and volvulus, or GDV. A dog with GDV can experience a number of potentially fatal complications, including septic shock, a perforated stomach, massive blood loss, and disruption of the blood clotting mechanisms. The exact cause of bloat is unknown. Large breeds of dogs built with big chests and narrow abdomens are more commonly affected. Excitable dogs, as well, are at risk since the stomach can develop bloat by filling with air during high-energy type activities such as barking, panting, excitement, and swallowing air while exercising. Clinical Signs and Symptoms Non-productive retching; vomiting small amounts of foam or saliva;restlessness; pacing; lying down and getting up again; weakness; lethargy; panting; abdominal distention. Diagnosis The examining veterinarian will base the diagnosis of bloat on an evaluationof the dog's symptoms and x-rays of its stomach. Because GDV can lead to shock and the release of toxins into the bloodstream, the veterinarian also may conduct tests such as a complete blood count, or CBC,a packed cell volume, or PCV, and an assessment of the total proteinpresent, or TP. A serum chemistry panel and a clotting profile are often needed. Description Gastric dilatation and volvulus, or bloat, occurs when a dog's stomach becomes so swollen with gas that it is unable to relieve the pressure. As the stomach becomes distended, it often rotates on its axis, cutting off blood flow to the stomach and often the spleen as well. Bloat can progress into a life-threatening illness requiring immediate emergency medical intervention. If the dog's stomach is not decompressed before the disease becomes severe, the enlarged abdomen will pose a dangerous threat to the circulatory system by preventing the blood in the stomach and the rear limbs from returning to the heart. This disruption of blood supply will stop the necessary amount of oxygen from being carried to the cells. Shock, a serious and potentially fatal condition, will result. As the dog's body goes into shock, there is a breakdown of the protective barriers that normally keep the bacteria inside the stomach, small intestines, and colon from releasing toxins into the bloodstream. Once the setoxins are let loose, the dog's blood pressure will start to plummet and the vital organs will not receive an adequate blood supply. Additionally, the dog's heart rate is often increased and may begin beating with an abnormal rhythm, a condition known as arrhythmia. If not closely monitored, arrhythmias can lead to additional circulatory disturbances or sudden death. Other serious complications may continue to threaten the dog's survival. One is called necrosis, which occurs when parts of the stomach wall begin to die because the blood supply to the stomach has been drastically reduced. Necrosis in turn can lead to perforation of the stomach and leakage of its contents into the abdominal cavity. The result is peritonitis, which has avery high mortality rate. In addition, the spleen may become twisted as a result of its attachment to the stomach, sometimes cutting off its life-supporting blood supply. Yet another potential complication, which may occur any time the body is so severely injured, is the development of disseminated intra vascularco agulation (DIC), an often-fatal condition in which the body begins form in many small blood clots within its vessels. These clots can plug up small vessels, preventing the blood from flowing properly and, as a result,damaging tissues in vital organs such as the kidney, liver, lung, and brain. Because of the large numbers of clots that have formed, the body will have used up the clotting factors and platelets that were available to stop hemorrhaging. Once a dog has begun hemorrhaging from DIC, it is usually fatal. Even if a veterinarian is able to regulate the dog's arrhythmia during emergency surgery, stomach perforation and DIC can occur independently -sometimes a full 24 hours after the blood pressure problem has been addressed. Often, the cause of death in dogs who die from bloat is a combination of factors. Transmission or Cause The cause of bloat is unknown. Large breeds built with deep chests and small abdomens, such as the Great Dane, Mastiff, Irish setter, golden and Labrador retriever, and the Irish wolfhound are more at risk for getting bloat because of their deep-chested body conformation. Aerophagia, or the swallowing of air, another risk factor for bloat, is often seen in very excitable dogs, or dogs with poor ability to breathe through the nose. Bloat can also be caused by another underlying disease that prevents the stomach from emptying itself at a normal rate, such as a tumor of the stomach. Treatment Once a veterinarian diagnoses the condition, the initial treatment will be directed towards stabilizing the dog and addressing any complications. Intravenous fluids are given very rapidly to increase blood pressure and to treat or prevent shock. Sometimes two intravenous catheters are needed to supply the dog with enough fluids to support it. Dogs with bloat are also given antibiotics to prevent them from developing an infection. The veterinarian will need to decompress the dog's stomach to decrease the pressure and improve blood flow. To assess the position of the stomach, he or she may take x-rays. The usual method for decompression is to insert a tube through the mouth into the stomach. The tube allows the passage of air and in gesta out of the stomach. If the stomach has twisted, and the tube cannot be inserted, it may be necessary to pierce the stomach with a hollow needle so that the gas can escape. If the stomach has twisted because of the bloat, surgery is generally required to reposition it. Surgery may also be needed to assess the health of the stomach wall and the spleen. If they are severely damaged, the spleen and parts of the stomach may need to be removed. Lastly, a procedure called gastropexy, in which the stomach is securely attached to the body wall, is performed to prevent any future twisting. With out a gastropexy, the recurrence rate may be as high as 50 percent. During recovery from this surgery, the dog is treated aggressively to prevent the development of shock, DIC, and infection. Prognosis The prognosis depends on a number of factors, the most important one being whether the dog receives medical treatment as soon as possible, typically before the condition becomes so debilitating that the animal has collapsed and is unable to walk on its own. Animals that are walking under their own power and are in minimal distress generally do better than animals that are collapsed or in a severe state of shock. If parts of the stomach and the spleen need to be removed, the prognosis is less certain. An a rythmia can also be a dangerous factor. Overall, the survival rate for more stable animals may be 80 to 90 percent. In severely affected animals, it may be 50 percent or less. Prevention Unfortunately, the reason GDV occurs is not fully understood at this time,but there are several recommendations for prevention, including: Feeding multiple smaller meals, rather than one large one Avoiding heavy exercise after meals Avoiding excitement after meals Storing food out of reach to prevent a dog from gorging itself. |
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