Overview of Gastric Dilatation-volvulus (GDV or Bloat) in Dogs
Gastric Dilatation-Volvulus (GDV), often referred to as “bloat”, “twisted stomach” or “gastric torsion,” is a serious condition caused by abnormal dilatation and twisting of the stomach. The condition is initiated by abnormal accumulation of air, fluid or foam in the stomach (gastric dilatation). Bloating of the stomach is often related to swallowed air, although food and fluid also can be present. Bloat can occur with or without volvulus, or twisting. As the stomach enlarges, it may rotate 90 degrees to 360 degrees, twisting between its fixed attachments at the esophagus (food tube) and at the duodenum in the upper intestine.
Volvulus can completely obstruct emptying of the stomach. The twist also prevents burping, so the dog cannot obtain relief of air or stomach contents by belching or vomiting. In fact, a hallmark symptom of torsion is nonproductive attempts at vomiting. The bloated stomach obstructs the return of blood from the veins in the abdomen leading to low blood pressure, obstructive shock and associated complications. The dog also may seem short of breath due to pain and the physical compression of the chest and diaphragm caused by the expanding stomach.
The combination of bloating and torsion seriously reduces the blood supply to the stomach (gastric ischemia) and this can lead to necrosis (death) of the stomach wall. Shock and lack of blood supply to abdominal organs break down the integrity of the gastrointestinal tract lining and permit toxins and bacteria to enter the blood stream. Abnormal blood clotting – disseminated intravascular coagulation (DIC) – may develop. The spleen can be damaged or begin to bleed because it is attached to the stomach by a membrane, and it becomes twisted and rotated abnormally as the stomach turns. Heart function is compromised due to lack of venous blood return. Irregular heart rhythms often develop such as ventricular tachycardia. Shock and death follow if the condition is left untreated or if treatment is initiated too late in this devastating sequence.
GDV is most common in deep-chested or large to giant breed dogs between two and ten years of age. GDV can also occur in other breeds, but this is comparably rare. Pure breed dogs are at higher risk for bloat. The breeds most commonly affected include the Great Dane, standard poodle, Saint Bernard, Gordon setter, Irish setter, Doberman pinscher, Old English sheepdog, Weimaraner, and the Basset hound.
GDV can sometimes be associated with eating or drinking before or after exercise. Risk factors may include once daily feeding and consumption of large amounts of food or water. For more information on risk factors, go to Is Your Dog at Risk for Bloat?.
What to Watch For
- Abdominal distension
- Abdominal pain
- Vomiting leading to nonproductive retching
- CollapseGDV is life-threatening. See your veterinarian immediately if you suspect bloat or GDV.
Diagnosis of Gastric Dilatation-volvulus in Dogs
The diagnosis can usually be made based on the history and physical examination.
- Physical examination should include abdominal palpation and auscultation of heart and lungs.
- After your dog has been stabilized and initial treatment begun, radiographs may be taken. A lateral abdominal view in right lateral recumbency with dog lying on the right side, is the view of choice for differentiation of simple dilatation from dilatation-volvulus.
- After initial stabilization and treatment, a complete blood count and blood biochemical tests may be performed. Blood tests help to define concurrent abnormalities that may influence the choice of anesthesia.
Treatment of Gastric Dilatation-volvulus (GDV) in Dogs
- Initial treatment of GDV will include emergency treatment for shock with intravenous fluids, drug therapy, and decompression of the stomach.
- Surgery is the recommended treatment to untwist and stabilize the stomach. To prevent recurrence, the stomach must be attached to the abdominal wall, known as gastropexy. If the spleen is badly damaged, it may need to be removed (splenectomy).
Home Care and Prevention of Bloat in Dogs
If you observe signs of GDV at home, see your veterinarian immediately. There is no recommended home therapy for GDV. Remember that giant-breed and deep-chested dogs are at increased risk.
Feed small frequent meals and limit water intake for one hour after eating, and avoid large volumes of water intake. Limit exercise after eating. Do not feed from elevated feeding bowls. Avoid stress.
For dogs that are at high risk for GDV, a prophylactic gastropexy is often performed.
Information In-depth on Gastric Dilatation-volvulus (GDV)
Gastric dilatation-volvulus (GDV) is a condition that is centered initially in the stomach, but eventually can affect the entire body. Some problems that can result are:
- Shock and cardiovascular complications
- Bleeding disorders
- Injured spleen
- Secondary infection
- Heart arrhythmias (irregular heartbeats). The arrhythmias are caused by poor oxygenation to the heart (myocardial ischemia), release of toxins, electrolyte abnormalities, acid-base abnormalities, and gastric receptor stimulation.
- Disseminated intravascular coagulation (DIC)
- Aspiration pneumonia
- Gastric necrosis
- Gastric ulceration
- Recurrence of dilation and/or volvulusThese problems can persist even as the GDV is successfully resolved. Other medical problems can lead to symptoms similar to those encountered in GDV, and it is important to exclude these conditions before establishing a definite diagnosis. They are:
- Gastric dilation without volvulus
- Gluttony bloat (gastric distention from overeating)
- Aerophagia, which is swallowing air due to difficulty breathing (dyspnea)
- Ascites, or fluid accumulation in the abdomen
- Torsion of the spleen
- Diaphragmatic hernia with stomach herniation
Veterinary care should include diagnostic tests and subsequent treatment recommendations.
Diagnosis In-depth of Canine GDV
Diagnostic tests are needed to recognize GDV, and exclude all other diseases, including:
- Complete medical history and physical examination.
- Clinical response to gastric decompression (passing a stomach tube or inserting a needle into the abdomen to relieve gas pressure).
- Your veterinarian should assess your pet for shock. It is important to monitor vital signs, airway, breathing, heart rate and to identify bleeding disorders.
- If the diagnosis is not clear, abdominal radiography (X-rays) is the first diagnostic test performed. An abdominal X-ray may reveal a large air-filled stomach with a soft tissue fold that appears to compartmentalize the stomach. This suggests that the stomach is twisted (volvulus). Air that is free floating in the abdomen suggests perforation of the stomach.
- After initial stabilization of the patient a complete blood count (CBC) and blood biochemical test may be performed. Electrolyte abnormalities may be present.
- An electrocardiogram (EKG) is often needed to monitor for cardiac arrhythmias.Additional diagnostic tests may be recommended on an individual pet basis, including:
- Arterial blood gas determinations may be needed to identify complications of shock.
- Repeat biochemistries if initial tests are abnormal.
- Blood lactate. This test may be prognostic as a higher level indicates a worse prognosis. It is believed that lactate levels greater than 6 mmol/L is associated with an increased mortality.
- Coagulation studies should be done and fibrinogen levels should be tested to identify disseminated intravascular coagulopathy.
Treatment In-depth of Canine GDV
Treatments for GDV may include one or more of the following:
- Initial therapy directed at treatment of shock and alleviation of gastric distension.
- Rapid administration of intravenous fluids. Fluid choice may very to treat shock.
- Antibiotic therapy is recommended to prevent complications of gastrointestinal injury.
- Administration of flunixin meglumine (Banamine) to decrease prostaglandin synthesis for shock as previously recommend but is current use is controversial. Corticosteroids such as methylprednisolone sodium succinate and dexamethasone were previously used to treat endotoxemia and shock was but is not currently recommended.
- Sedation or anesthesia to perform gastric decompression and lavage.
- Gastric decompression and lavage is a procedure in which a large, flexible rubber or plastic tube is passed through the mouth into the stomach. This is done to relieve pressure and to remove the stomach’s contents. Decompression does relieve gastric dilatation, but does not correct a volvulus (twisting) if that is also present. Decompression also decreases pain and discomfort, improves venous blood return to the heart and helps reduce further injury to the stomach lining.
- Once the tube is placed into the stomach, the stomach is flushed with warm water to remove fluid and food debris. This is called gastric lavage.
- If the tube does not advance, a procedure called gastrocentesis may be needed. This procedure involves clipping hair over the side where the stomach is located and inserting a needle through the wall and into the stomach to remove air. This removal of air and pressure will often allow a tube to be inserted.
- A temporary pharyngostomy tube, which is a tube that goes from behind the jaw to the stomach, can be placed if the dog is too unstable for surgery due to cardiac arrhythmias or other complications. However, in most cases of GDV, the next step is abdominal surgery.
- Surgery is the definitive treatment for GDV. While gastric decompression via tubing can effectively treat this disease, surgery is the best treatment and follows shock therapy, gastric decompression and arrhythmia stabilization.
- If volvulus is present, surgery is needed to return the stomach to its normal position. Surgery should not be delayed unnecessarily. Surgery is also essential to allow visual inspection of the stomach wall because this tissue may not be viable if it has been deprived of blood supply for very long. During surgery, the stomach is repositioned, the spleen examined (and untwisted), devitalized (dead) stomach wall can be removed, and the spleen can be removed if it does not become normal after untwisting.
- If the patient is stable after these procedures, a gastropexy is usually performed, which is a procedure to attach the stomach to the abdominal wall and help to prevent recurrence of GDV. There are several surgical techniques for gastropexy such as tube gastropexy, circumcostal gastropexy, belt loop gastropexy and muscle flap (incisional) gastropexy. Each of these techniques has proponents. In a comparison between the different surgical types, all were found to have similar effectiveness. The tube gastrotomy was found to have the most complications. The best technique is the one that your veterinarian is familiar with and can perform.
- Unfortunately, some dogs suffer extensive injury to their stomach such that the bulk of muscle is devitalized or dead, especially if the GDV has been prolonged and care was not sought quickly. In such cases, euthanasia may be the only course as removal of the stomach is not a practical option.After surgery, post-operative care by your veterinarian may include:
- Monitoring for 2 to 4 days that includes observation for arrhythmias using and electrocardiogram. Severe arrhythmias may be treated with drug therapy such as potassium supplementation, Lidocaine or Procainamide.
- Monitoring of urine output
- Post-operative pain treatment
- Fluid therapy to ensure that an adequate blood potassium level is maintained
- Post-operative wound care
- Antibiotics are usually continued. Even with the sterile procedures employed during surgery, there is the risk that devitalized stomach tissue or intestine injured by shock (low blood flow) may allow bacteria to move into the circulation.
- Reduction of stomach inflammation can be treated with cimetidine (Tagamet®), ranitidine (Zantac®) or famotidine (Pepcid®).
- Enhancement of gastric motility can be treated with Metoclopramide HCl (Reglan®) or Cisapride. Gastric motility is often abnormal post-operatively due to gastric distension, lack of blood flow to the tissue, and the surgery itself.
Most dogs that die from complications of GDV will do so within the first four days post-operatively. The mortality rate is approximately 15% for dogs treated surgically. The mortality rate is more than 30% for dogs treated surgical for which gastric resection is required. With surgery, recurrence rates are less than 10%.