Dear Dr. Dog: I just adopted a Great Dane and have heard that something called canine bloat could be a problem because of his size. Exactly what is this condition, how dangerous is it, and how can I prevent it?
You are wise to educate yourself about canine bloat, or gastric dilatation-volvulus (GDV), since it is the number-one cause of death for several large and giant dog breeds. It occurs when the dog’s stomach becomes twisted, and can quickly become life-threatening as gas builds up but cannot escape. The stomach compresses nearby blood vessels as it extends with gas, and the stomach itself may die from inadequate blood flow. Toxins that accumulate in the dying tissues then spread through the body, causing havoc in other organ systems.
The breed with the highest average lifetime likelihood of a bloat episode is indeed the Great Dane, at 42.4%. Other breeds at higher-than-average risk include the Bloodhound, Irish Wolfhound, Irish Setter, Akita, Standard Poodle, German Shepherd, and Boxer, although any deep-chested dog may be prone to the disease.
In a study of over 1,900 dogs representing eleven different breeds at the Purdue University School of Veterinary Medicine, several risk factors were identified.
Dogs with the greatest risk of developing bloat have deep and narrow chests, and lean dogs are at higher risk than overweight dogs. (This does not mean, of course, that overweight dogs are generally healthier than lean dogs.)
Risk is also higher for older dogs. For large breeds, the risk of developing bloat goes up 20 percent each year after the age of 5. For giant breeds, it goes up 20 percent each year after the age of 3. First degree relatives (i.e., parents, littermates, or offspring) of dogs that have had bloat have a 63 percent greater risk of developing bloat themselves.
Dogs that eat quickly have a 15 percent higher risk, and several other diet-related factors were associated with a higher incidence of bloat. These include feeding only dry food or feeding a single large daily meal.
During the past 30 years there has been a 1,500 percent increase in the incidence of bloat, which coincides with the increased feeding of dry dog foods. Mixing table food or canned food into dry food is one way to decrease the risk of bloat.
As for feeding one large meal a day, this can weigh down the stomach and stretch the hepatogastric ligament, which helps maintain the stomach’s normal position in the abdomen. Dogs that have bloated were found to have a much longer hepatogastric ligament, probably due to chronic stretching. This could also explain why bloat risk increases with age.
Several popular theories regarding bloat were not substantiated during the study. There was no correlation of bloat risk to exercise before or after eating, as most dogs bloated in the middle of the night with an empty, gas-filled stomach. There was also no correlation to vaccinations, to the brands of dog food consumed, or to the timing or volume of water intake before or after eating.
One widely touted bloat preventative has been to raise the height of food and water bowls, but this was found to actually increase risk by 110 percent. Do not raise the food!
The Purdue study also found that fearful, nervous, or aggressive dogs had a much higher incidence of bloat than did dogs perceived by their owners as having happy temperaments. Stress can also be a precipitating factor, and many dogs bloat after recent kenneling or a recent long car trip.
Approximately 30 percent of dogs that develop bloat die or must be euthanized. This can be due to shock, cardiac arrhythmias (fatal irregular heart beats), or the rupture or death of the stomach wall.
Emergency treatment of bloat begins with alleviating the gas pressure by passing a rubber tube down the mouth into the stomach. This is followed by emergency surgery to un-twist the stomach.
The most important aspect of bloat surgery is a “gastropexy.” This procedure attaches the stomach wall to the body wall to prevent it from twisting in the future. Studies have shown that 76 percent of dogs that do not have a gastropexy performed after their first episode will bloat again.
For breeds that are at high risk we now recommend having a preventative gastropexy performed instead of waiting for bloat to occur. This surgery is usually performed at the time of neutering or spaying, but can be done at any time in a dog’s life.
At our hospital, we have been performing this procedure using laparoscopy since 2003, which requires only two small incisions on the side of the abdomen. The procedure results in permanent fixation of the stomach to prevent the organ from twisting, and allows a dog to recover far quicker and with less discomfort than traditional surgical gastropexy procedures.
Relax and enjoy your new Great Dane companion, but take care to decrease his risk of bloat by heeding the precautions mentioned in this article.
Dr. Franklin Utchen has been practicing veterinary medicine in San Ramon since 1989 and currently co-owns Bishop Ranch Veterinary Center & Urgent Care. His special interests include Orthopedic and Soft Tissue Surgery, Internal Medicine, Emergency/Critical Care, Dentistry, and Anesthesiology/Pain Management. Direct questions or comments to firstname.lastname@example.org.