Natural Standard Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
Bacteremia, bloat, cardiac arrhythmia, celiotomy, DIC, disseminated intravascular coagulation, elevated feeders, gastric decompression, gastric dilatation, gastric dilatation-volvulus, gastric torsion, gastric volvulus, gastropexy, GDV, Great Danes, hypoxia, linea alba, sepsis, splenectomy, torsion, ulceration.
Bloat, also known as gastric dilatation-volvulus (GDV), is a serious and potentially life-threatening condition that may occur in dogs. Bloat occurs when the stomach fills with gas and/or fluid and distends, rotates, and obstructs other organs and blood flow. A dog with bloat often looks bloated or inflated, due to the accumulation of gas and/or liquid in the abdomen. If left untreated, the distended stomach may block the flow of blood and oxygen to other organs, possibly leading to serious infection, organ failure, and death.
The risk of death from bloat increases with the severity of the disease. Gastric dilatation, the first stage of bloat, occurs when the stomach fills with gas or fluid. This symptom alone may be relatively harmless. However, as the pressure from the gas builds, this may cause breathing difficulties. If the condition worsens, gastric volvulus, also called gastric torsion, may occur. This is the stage of the condition during which the stomach twists and rotates, potentially restricting blood flow and oxygen supply to other organs.
According to the American College of Veterinary Surgeons (ACVS), about 60,000 dogs per year develop bloat. According to the American Society for the Prevention of Cruelty to Animals® (ASPCA®), even with treatment, an estimated 24-40% of dogs with bloat die from the condition. The American Animal Hospital Association (AAHA) states that some dogs may die in as few as 30 minutes. This rate may increase if the dog has had a splenectomy (removal of spleen), pre-existing heart condition, stomach removal, or exhibits symptoms for more than six hours.
Some dogs may have an increased risk of developing bloat. Dogs with an increased risk include large breeds with narrow chests and dogs with high stress or anxiety. Great Danes are among the breeds with the greatest risk. However, according to the ACVS, bloat has been reported in almost all breeds. Eating large meals, exercising after meals, and using elevated feeders may also increase the risk of bloat.
Types of the Disease
General: Bloat is a life-threatening condition that may occur in dogs. A dog may swallow excess air while eating a large meal, or while eating too quickly. Exercise following a meal may also increase the amount of air and pressure within the stomach, leading to additional complications, including rotation and twisting of the stomach. According to the American College of Veterinary Surgeons, the lack of oxygen and blood flow caused by the increased pressure and twisting within the stomach may place the dog in shock and ultimately be fatal.
Gastric dilatation: Gastric dilatation, the first stage of bloat, occurs when the stomach fills with gas and/or fluid. This symptom alone is not necessarily dangerous and may frequently occur in some dogs. If the air in the stomach is released through flatulence and burping, the pressure does not increase and the dog will continue to digest food normally. If the stomach continues to expand and dilate, the pressure within the stomach may increase. This increased pressure may lead to breathing problems, and ultimately cause the stomach to twist and rotate.
Gastric volvulus (torsion): Gastric volvulus, or torsion, is the second stage in bloat. Torsion occurs when gastric dilatation becomes severe and the pressure within the stomach cannot be expelled. The expanded stomach may then twist and rotate, which restricts blood flow to other organs. A vulvulus is defined as a stomach rotation greater than 180 degrees, while a torsion is described as a rotation less than 180 degrees. However, most sources used these terms interchangeably. Once the blood supply is cut off, the dog's condition may quickly deteriorate. According to many sources, the potential for bloat to be fatal at this stage is high.
General: Although most sources noted that the risk factors associated with dog bloat are not fully understood, certain breeds and activities may be linked to an increased risk for bloat. Among the most notable risk factors is breed size. Larger breeds, such as Great Danes, are at the greatest risk of this condition. The temperament of the dog, using elevated feeders, and eating large meals are also potential risk factors.
Age and gender: Increasing age does not predispose a dog to developing bloat. However, incidence of bloat increases with increasing age. Bloat is extremely rare in puppies less than one year old. Bloat is most common among dogs aged 7-10 years. Some studies have reported a potential ink between male gender and increased risk of bloat.
Disposition: Dogs with an anxious or nervous temperament may have an increased risk of developing bloat. According to several sources, the stress of living in a kennel or shelter may also increase the risk of bloat.
Diet: Certain dietary factors may increase a dog's risk of developing bloat. Dogs that are consistently fed the same type of food, especially dry dog food, may be at an increased risk of bloat than dogs fed a more varied diet. According to several sources, dogs fed a combination of dry dog food, table food, and canned food may have a reduced risk of developing bloat. Higher amounts of corn-based ingredients in dry dog foods have been associated with increasing risk of bloat; however, studies have not proven this link to be significant. Evidence on how or why corn-based ingredients in dry dog foods may increase risk of bloat is lacking.
Feeding habits: Dogs that eat one or two large meals daily and dogs that eat quickly may be at a greater risk of developing bloat. Dogs that are active before or after meals may also have an increased risk of bloat. There is some evidence that suggests elevated feeders, which are feeding dishes or bowls that are raised off the ground, may also be a risk factor. However, the reason for this associated risk is unknown. Conversely, some sources suggest that elevated feeders may reduce the risk of bloat by reducing the amount of swallowed air and gulping while eating. Due to the conflicting evidence, there is controversy among the veterinarian community regarding the use of elevated feeders. However, most sources suggested avoiding elevated feeders for dogs that may be at risk for bloat until further research confirms or negates previous findings.
Breed and physique: Dogs with large, narrow, and deep chests, such as Great Danes, are more likely to develop bloat. Chest size is determined by genetics. According to a study published by the University of Purdue, some breeds may be more prone to bloat than others. A risk ratio was developed based on chest size and other physical attributes to determine the risk of bloat by breed. Based on these risk ratios, researchers developed a ranking system listing dogs with the highest risk down to those with the lowest.
According to the study, the highest to lowest risk ranking is as follows: Great Dane, Saint Bernard, Weimaraner, Irish Setter, Gordon Setter, Standard Poodle, Basset Hound, Doberman Pinscher, Old English Sheepdog, German Shorthaired Pointer, Newfoundland, German Shepard, Airedale Terrier, Alaskan Malamute, Chesapeake Bay Retriever, Boxer, Collie, Labrador Retriever, English Springer Spaniel, Samoyed, Dachshund, Golden Retriever, Rottweiler, Mixed, Miniature Poodle.
Overall health: Some studies have reported that dogs with a history of major or chronic health problems (such as heart worm, kennel cough, infections, and obesity) during the first year of life may have an increased risk of bloat. Underweight dogs also have a significantly higher risk of developing gastric dilatation-volvulus (GDV) than dogs having a healthy weight. Dogs that have undergone a splenectomy (removal of the spleen) may also have an increased risk of the condition.
According to many sources, bloat is caused by excess swallowed air. However, it is not fully understood what inhibits dogs with this condition from releasing the excess air through burping and flatulence. Many dogs become bloated (gastric dilatation), and are able to release the air without complication. Research is ongoing to determine what prevents the release of air, and why certain dogs may be prone to the condition.
Although the causes of bloat may not be fully understood, researchers have established an association between certain risk factors and bloat. This includes dogs with large, deep chests, certain dog breeds, and eating one large meal per day.
Signs and Symptoms
General: Symptoms of bloat typically come on suddenly, without warning, and progress quickly. A dog may go from being healthy to critically ill within a few hours. As blood flow is impeded and tissues are deprived of oxygen, vital organs may begin to die leading to cardiac collapse (the heart becomes unable to sufficiently pump blood through the body) and death. For this reason, reaction time is very crucial for survival with bloat and being able to recognize the symptoms is very important. If the dog begins to exhibit any signs of bloat, a veterinarian should be consulted immediately.
Gastric dilatation signs: During the first stage of bloat (gastric dilatation), the dog may experience stomach pain, swelling of the abdomen, gagging, or excessive salivation. Dog owners may also notice that the dog appears anxious or restless, lethargic, and is drooling excessively. The dog may stretch and the abdomen may be swollen and appear to be rounded, usually visible just behind the rib care. The abdomen may feel hard and be tender to touch.
Gastric volvulus signs: Gastric dilatation may become more severe if treatment fails or if the initial bloating is not treated and pressure within the stomach continues to expand. The second stage of bloat, gastric volvulus or torsion, causes the stomach to rotate. During torsion, the dog may experience shallow breathing, panting, weakness, increased heart rate, or depression. The dog may also appear to attempt to vomit, continuously retch, and have pale gums. If these symptoms continue to progress, the dog may suddenly collapse.
General: Most animal organizations recommend that dog owners seek immediate veterinary attention if their dogs exhibit any signs of bloat, including swollen stomach, gagging, or excessive drooling. There is no single diagnostic test for bloat. Veterinarians may request several tests, including a chemistry panel, which examines various metabolic processes in order to rule out other conditions that may cause similar symptoms as bloat. Bloat will often be suspected if large breeds with an increased risk of the condition are presenting abdominal pain or swelling.
Physical examination: A veterinarian will perform a physical examination of the dog for external signs of bloat. The veterinarian may examine the stomach by gently pressing on the abdomen and listening to the abdomen with a stethoscope.
Complete blood count (CBC): A complete blood count (CBC) offers a comprehensive analysis of the dog's blood and allows the veterinarian to determine if any other underlying conditions may be present. CBC tests the number of white and red blood cells, platelets (clotting factors), and hemoglobin (a molecule that carries oxygen) in the blood. It also examines the type of white blood cells in the blood, the percentage of red blood cells per blood volume, the percentage of hemoglobin in a red blood cell, and the size and distribution of red blood cells in the blood. Changes in these values from normal may be indicative of infection, bleeding, or inflammation. For example, if the overall white blood cell count is higher than normal, the dog may have an infection, cancer, or other condition.
Chemistry panel: A chemistry panel is a blood test that examines the blood serum (liquid), as opposed to blood cells, by spinning a blood sample in a centrifuge to separate serum from cells. Panels may be performed in house or sent out to a laboratory. Chemistry panels usually test for 13 different chemical components found in the serum at different levels. This includes potassium, sodium, creatinine, blood urea, protein, calcium, glucose, bilirubin, albumin, cholesterol, albumin, globulin, phosphatase, and alanine amino transferase (ALT). These components demonstrate if various organs and systems such as the kidneys and immune system are functioning properly.
A dog with bloat may have elevated urea, creatinine, ALT, and potassium levels. This indicates kidney and/or heart problems. Other components that may be elevated are creatine kinase (CK), aspartate transaminase (AST), and phosphorus levels, which may be included in the chemistry panel or tested separately. This indicates liver, heart, and/or kidney problems, which may be due to organ obstruction.
Urinalysis: Urinalysis tests the liquid and solids in a urine sample for various chemical components. Different components of the urine sample are tested to understand the health of the liver, bladder, pancreas, kidneys, and other organs. Urinalysis is usually composed of three parts. Cloudiness of the overall sample determines how concentrated the urine is (how much water and solids are in the sample). The liquids and solids are separated and tested. Sediment analysis tests levels of minerals, bacteria, and white blood cells. Chemical analysis tests for many chemical components in the liquid, including acidity (pH), nitrites, glucose, and protein.
Radiograph: Radiographs use x-rays to image the inside of the body. If bloat is suspected, a veterinarian may perform a radiograph of the abdominal cavity to view stomach extension or any movement of the gastrointestinal organs. For example, a folding of the stomach may be represented on a radiograph by a line between two sections of the stomach: the fundus (located near the esophagus at the top of the stomach) and the pylorus (located near the intestine at the bottom of the stomach). If the dog is too mobile, anxious, or is in pain, sedation of the dog during radiography may be necessary. Any movement may cause blurring of the image. A lead apron or vest may be placed over areas that are not being x-rayed to reduce radiation exposure to other areas.
Electrocardiogram (ECG): An electrocardiogram (ECG) provides information on heart function. Dogs with bloat may experience cardiac arrhythmias, which are abnormal electrical activities in the heart, such as rapid or irregular heartbeat.
Blood gas analysis: Blood gas analysis determines the oxygen levels and acidity of the blood. The test is usually ordered if the dog experiences respiratory problems such as shortness of breath. For the analysis, a sample of arterial blood is taken by syringe and sent to a diagnostic laboratory for testing. The results may show that the dog may not be able to take in enough oxygen or expel enough carbon dioxide.
Disseminated intravascular coagulation (DIC): Disseminated intravascular coagulation (DIC) is a potential complication of bloat. DIC is a serious condition caused by the buildup of fluid and/or gas in the stomach. DIC is a bleeding disorder caused by the formation of blood clots throughout the circulatory system. This may disrupt blood flow and damage organs.
Hypoxia: If bloat is not treated quickly, hypoxia, which is the lack of oxygen to tissues, may occur. If left untreated, hypoxia may lead to cell death, particularly in the liver and kidneys, leading to organ failure. The gastrointestinal tract is at greater risk of hypoxia. Additionally, hypoxia may lead to cardiac arrhythmias, or irregular heartbeats.
Organ failure, sepsis: Due to the nature of bloat, the entire gastrointestinal tract is at risk of cell death. This presents additional danger during or following treatment. As gas is released and the stomach is returned (surgically) to its original position, toxins that have locally accumulated in the stomach are released into circulation. Toxins circulating in the body may cause additional cardiac arrhythmias, acute kidney failure, and liver failure. Toxins and bacteria may build up and travel to vital organs, even after treatment. This may lead to organ failure, infection (bacteria in the blood), and sepsis (whole-body inflammation).
General: Bloat is a serious condition that requires immediate medical attention. The condition occurs when the stomach fills with gas and/or fluid and distends, rotates, and/or obstructs other organs and blood flow. Treatment usually involves stabilization, decompression, and possibly surgery.
Stabilization: Veterinarians will first stabilize the dog by administering oxygen and intravenous fluids. The dog may also be prescribed pain killers and/or antibiotics. If the dog is in shock, saline solutions or glucocorticoids (steroids used to treat inflammation) may be given. Sedation may also be required in order to fully examine the dog.
Decompression: Pressure on the gastrointestinal tract is relieved through gastric decompression, which allows gas and/or liquid to leave the body. This is the first mode of treatment in most bloat cases to stabilize the dog. The dog's mouth is taped shut around an oral speculum (implement with a hole). A tube is inserted through the speculum, down the esophagus, and into the stomach while the dog lies on its back or side. Gas will be released through the tube once it enters the stomach. Liquid may be removed with suction. Once gas and liquid are removed, saline or water is used to flush out the stomach.
In some cases, it may not be possible to pass a tube through the esophagus. This may require the use of a catheter (large needle). A small area below the rib cage is shaved and sterilized. The catheter is inserted into the stomach through the skin. In dogs that are in critical condition, a temporary gastrotomy may be required to relieve pressure. A temporary gastrotomy is an incision made in the skin and through the abdominal muscles, exposing the stomach. The stomach is sutured, or stitched, to the incision, and the stomach is emptied and rinsed with water or saline.
Surgery: After the dog is stabilized, surgery is usually performed to determine the health of the vital organs, including the liver and stomach. The dog is anesthetized and a celiotomy (an incision in the stomach) is performed. The veterinarian examines the stomach and surrounding tissues for signs of necrosis (death of cells or tissues) or other damage. Organs that cannot be repaired may be removed. Splenectomy (removal of spleen) is a common procedure in dogs with bloat. Sections of the stomach wall may also need to be removed or repaired
In dogs with volvulus (rotation of the stomach), the stomach may need to be repositioned. The stomach is often shifted or twisted in dogs with bloat. Gastropexy is a common procedure in dogs with volvulus. The stomach is sutured to the abdominal wall, preventing the stomach from rotating again if the dog develops bloat in the future. Veterinarians may use laparoscopes, which are small fiberoptic surgical instruments with cameras that can be inserted through a small incision for the procedure. There are several types of gastropexy, which vary by technique, but the purpose of the procedure is to prevent future developments of gastric volvulus. Incorporating gastropexy is a technique that adheres the stomach to the linea alba (connective tissue located in the middle of the abdomen). Incisional gastropexy is a technique that adheres the stomach wall to the abdominal muscles. Belt-loop gastropexy is a technique that fixes abdominal wall to a flap of musculature. Circumcostal gastropexy loops a flap of muscle tissue around a rib and then fixes it to the abdominal wall.
Post-operative: Dogs may be hospitalized for several days after surgery. Food is usually withheld for as many as two days. Metoclopramide (medication that is usually prescribed to treat ulcers and gastric reflux) may be prescribed to treat post-operative vomiting.
Several complications for bloat and/or surgery are possible. Dogs may develop cardiac arrhythmias, the treatment for which includes intravenous fluids and lidocaine hydrochloride (an anesthetic), procainamide (an antiarrhythmic medication), or magnesium sulfate (a nutritional supplement). Vital organs should be carefully monitored for hypoxia (or tissue oxygen deprivation). Antibiotics may be used to treat infections.
After hospitalization, preventative measures may be taken to prevent any complications, including providing the dog with smaller meals and avoiding exercise after meals. Movement is possibly restricted for several weeks to allow proper healing.
Note: Some of the integrative therapies below may have been used or studied in humans. A qualified veterinarian should be consulted before making decisions about the medical treatment of animals.
Charcoal: Charcoal biscuits are edible biscuits made with activated charcoal to help prevent and relieve gas buildup in canines. Activated charcoal biscuits are designed to absorb excess gas in the stomach and bowels. Charcoal biscuits may be found in pet stores and some health food stores. Caution must be advised when using charcoal biscuits because, in addition to absorbing gas, charcoal may also absorb important nutrients from the dog's food.
Ginger: Secondary sources suggest sprinkling fresh or dried ginger in the dog's food to prevent gas buildup. Ginger to prevent gas build up in humans is a traditional or theoretical use that lacks sufficient evidence. Ginger is considered safe in canines.
Psyllium: Psyllium is a soluble dietary fiber and a main ingredient in many commercially available bulk laxitives, such as Metamucil®. Psyllium is safe for use in canines. The scientific evidence for psyllium's use for gas in humans is unclear or conflicting. In humans, after taking 30g of psyllium for seven days, gas transit was slowed by decreasing bolus propulsion to the rectum. Secondary sources recommend adding one or two tablespoons of a psyllium-containing bulk laxative to the dog food daily. The scientific evidence for psyllium's use for gas in humans is unclear or conflicting, and further research in canines is necessary. Flatulence is a minor side effect associated with psyllium.
Thyme: Secondary sources suggest sprinkling a few tablespoons of fresh or dried thyme in the dog's food to prevent gas. Thyme to prevent gas in humans is a traditional or theoretical use that lacks sufficient evidence. Thyme is considered safe in canines.
Yogurt: Adding 1-2 teaspoons of live yogurt cultures to a dog's food may help prevent gas production. Live active cultures help to wipe out bacteria that produce bad-smelling gas. If a dog has problems with dairy, a soy live culture yogurt has been a suggested substitute. Further research is necessary to further evaluate safety and effectiveness in canines.
Education: Some dogs, particularly large breeds, are predisposed to bloat. Educating owners about the signs and symptoms of bloat may promote owners to seek prompt medical attention when signs and symptoms are observed in pets.
Small meals: Feeding a dog 2-3 small meals daily instead of one large meal may help prevent bloat. Restricting water intake to only after meals may also help. In multiple dog households, owners are advised to feed dogs at risk for developing bloat separately from others. Dog-owners should also restrict their dogs from participating in any vigorous activity or stress for 1-2 hours before and after meals.
The American Animal Hospital Association (AAHA) recommends pre-soaking food in water for 30 minutes before feeding and preventing dogs from eating foods that cause gas. It also cautions owners against using raised dishes, also called elevated feeders, which encourage dogs to eat at shoulder height. There is some evidence that elevated feeders may contribute to the development of bloat. However, some other sources recommend using elevated feeders for dogs as a means of preventing bloat. Owners should talk to their veterinarians about their dog's risk of bloat and the use of elevated feeders.
Medication: Over-the-counter anti-flatulence medications containing simethicone (Gas-X®) have been administered to dogs prior to stressful events. Simethicone relieves gas by breaking down large gas bubbles into smaller bubbles, which are theoretically easier for the stomach to pass.
In dogs at high risk of bloat, medicinal prevention with metoclopramide hydrochloride (Reglan®) may be used. Metoclopramide is used in humans to combat painful intestinal gas by decompressing the stomach and intestines to force the gas out. A veterinarian should be consulted before beginning any drug regimen.
Gastropexy: Gastropexy is a common surgery to prevent the reoccurrence of bloat in dogs. The stomach is sutured to the abdominal wall, preventing rotation or twisting if the stomach fills with gas and/or fluid in the future. Prophylactic (preventative) gastropexy may be performed in some dogs that have not had bloat but may be at high risk of developing the condition.
This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
American Animal Hospital Association (AAHA). www.aahanet.org
American College of Veterinary Surgeons. www.acvs.org
American Society for the Prevention of Cruelty to Animals® (ASPCA®). www.aspca.org
American Veterinary Medical Association® (AVMA®). www.avma.org
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Natural Standard: The Authority on Integrative Medicine. www.naturalstandard.com
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Copyright © 2013 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.
March 22, 2017