Bloat causes the stomach to swell up (or "bloat"). The reasons for the swelling remain elusive and will be the subject of additional studies. The dog cannot expel the gas and the stomach continues to swell until it twists (often as much as 360 degrees). This condition is called acute gastric dilatation volvulus (GDV syndrome) or torsion. Torsion is a life-threatening situation. If the stomach twists, its cavity becomes sealed off, closing off its upper and lower openings through which gas may normally escape. The swollen, distended stomach puts pressure upon the spleen, liver, pancreas, heart, and lungs, compressing nerves and blood supplies, quickly resulting in shock and death. Immediate surgery is the only treatment for this condition.


Strangulationis a form of bloat affecting the intestines. A loop of the intestine becomes constricted (strangulated) by slipping through an abnormal opening. This can happen when the dog has adhesions in its abdominal cavity, as often develop after abdominal surgery.


Intussusception occurs when a section of the intestine telescopes into itself. This condition is more common in puppies than adults and occurs most often after a long siege of diarrhea.  It is a life-threatening condition requiring immediate veterinary attention.


In a simple attack of bloat, in which the stomach fills with gas, the veterinarian will insert a tube down the throat, relieve the gas, pump out the stomach and give the stomach a thorough washing. Acute GDV or torsion, strangulation, and intussusception all require immediate veterinary care and surgery. Post-operative treatment for shock requires prolonged hospitalization. In the case of torsion, the stomach should be surgically "tacked down" to the body wall to prevent the twist from occurring again, because once a dog suffers from bloat, it will most likely happen again, often within days of the first attack. For strangulation and intussusception, surgery is needed to repair the intestines, and the dog also requires prolonged hospitalization for treatment of shock.


The tragedy of this disorder is how frequently it occurs when the owner is not home, but returns to find their Leonberger has died from GDV. It is a disease that strikes suddenly without warning, and is fatal unless immediate veterinary care is provided. Symptoms to watch for include extreme restlessness, excessive salivation, drooling, and an attempt to vomit or defecate. As the condition progresses, the stomach area appears swollen and the dog shows signs of pain when the abdomen is pressed. Rapid breathing, pale-colored mouth membranes and collapse are signs of shock due to a more advanced phase of bloat. If untreated, a dog will die within a short time. An alert owner who recognizes the early signs of a simple attack of bloat and gets immediate medical attention for his Leonberger may prevent the more severe form of acute GDV or torsion. Sometimes a dog will progress from bloat to torsion in minutes, so do not attempt to medicate your Leonberger, get it to a veterinarian immediately. Because time is so important in saving a bloated animal from death, it is a good idea to know where your local Emergency Pet Clinic is located (if your own veterinarian does not cover emergencies), and the quickest routes there. Do a dry run before the emergency exists and you will save precious moments if an emergency does develop.


Dr. Larry Glickman at the School of Veterinary Medicine at Purdue University completed the most comprehensive study of this disorder in 1998. The Akita, a breed that I have worked for in many areas for more than 25 years, participated in this study. The Akita was selected because it is in the top ten of breeds prone to suffer GDV.  Dr. Glickman’s study provided the following conclusions:

   The incidence of GDV has increased by 1,500% over the past 30 years.


   Thirty percent of all GDV cases are fatal. In contrast, dogs properly treated have an 80% probability of surviving a bloat episode.


   The recurrence rate of GDV in dogs conservatively treated for bloat i.e., without surgery, approaches 100%. The recurrence rate following gastropexy is less than 5%. Always insist on immediate surgery for your Leonberger, do not bring your dog home without corrective surgery.


•    Personality is a major predictor of GDV, the happy, easy-going dog has a lower risk of GDV. He suggests using behavior modification with anxious, fearful dogs.

   The incidence of GDV increases with advancing age. The increased risk begins at three years of age.

•    Do not breed dogs if a first-degree relative has bloated and do not breed dogs that have bloated. Having a grandparent, parent or sibling with GDV increases the risk of bloat.

   Males and females bloat almost equally.

•    Spaying and neutering have no effect
on the incidence of GDV.

•    Dogs characterized by their owners as chronically underweight are at higher risk than dogs characterized as average weight or even overweight.

•   The faster a dog eats, the greater the risk of bloat. This increased risk may be related to gulping air while eating. Reduce the eating speed of your Leonberger.

 •   Seventy percent of bloat cases occur late at night or early in the morning. Dr. Glickman is investigating a swallowing disorder as a possible contributing factor.

   There is a relationship between dogs with intestinal gas and dogs that bloat. Dogs that belch often have a 60% increased risk of bloat. Dogs with frequent bouts of flatulence have a 20% increased risk.

  Elevating the food bowl increases the risk of GDV.


   Dogs fed only dry food are at increased risk, while dogs fed a mix of dry food with table scraps are at decreased risk.


•    Dogs fed dry dog foods preserved with citric acid were at a higher risk of bloat; moistening the dry dog food containing citric acid further increased the risk.


   Feeding dry food containing rendered meat with bone among the first four ingredients decreased a dog’s risk of bloat by 53%.

•    Feeding multiple small meals reduces the risk of bloat.

   Having water available at all times reduces the risk.


   In high-risk breeds (like Akitas), consider having a prophylactic gastropexy done when the dog is spayed or neutered. The recovery is not very different than for sterilization alone, and the cost of the procedure is considerably less than an emergency surgery. (Approximately $3,000 compared to an additional $200.)


Is a raw food diet a factor in prevention of this disease? We will have to wait until Dr. Glickman completes his dietary-management study. The “Natural Akita” email list, which is comprised of advocates for the raw food diet, claim one case of bloat in an Akita since its inception in 1997--that could be coincidence.


Is Bloat A Neurological Disease?


My experience with bloat ended successfully for my Akita, Tootsie--she expanded like a balloon five hours after eating, was rushed to the emergency hospital two blocks from home and underwent successful gastropexy. Her surgeon was amazed at the complete lack of motility; he mentioned that in all GDV surgeries he had performed on various breeds, gastrointestinal motility was lacking in each dog. I assisted the veterinarian in washing undigested food from Tootsie’s stomach, food that she had eaten three days earlier.


His statement led me to research “motility,” the propulsion of food along the length of the digestive tract. What activated the smooth muscle contractions and why would this action cease, leaving undigested food in the stomach? Time out for a simple anatomy lesson! 


The dog's nervous system is comprised of the central and peripheral/autonomic nervous systems. The central nervous system consists of the brain and the neural tube running the length of the spinal cord. The brain is the body's central computer, analyzing and processing all information both internally and externally. Based on external stimuli, the brain decides a course of action, and relays the information through the central nervous system to the body or to a specific organ. Sensory nerves carry information to the brain and spinal cord; motor nerves carry signals back to the body, to spur movement of the muscles, or to stimulate glands into activity.


Dr. Zen of the Gastrointestinal Research Laboratory, Gunma University, Maebashi, Japan has been studying motilin, which is an important factor in controlling the pattern of smooth muscle contractions in the upper gastrointestinal tract. Motilin is considered a hormone—a “housekeeping hormone,” which is secreted into the circulation at intervals of every one hundred minutes, to sweep out undigested material from the stomach and small intestine. Motilin also stimulates secretions of bile and pancreatic enzymes into the duodenum.


Very little is known about the control of motilin. Apparently, it is stimulated by cholinergic neurons in the enteric nervous system, which is a part of the autonomic nervous system. The enteric nervous system controls all of the digestive processes from the secretion of motilin, to the propulsion of food through the gastrointestinal tract. Enzyme secretions from the pancreas and bile from the gallbladder are controlled by motilin. The enteric nervous system contains sensory neurons, inter-neurons, and motor neurons. Its circuitry can autonomously sense the tension, and the chemical environment in the gut and regulate blood vessel tone, motility, secretions, and fluid transport. The system is itself governed by the central nervous system.

Organophosphate insecticides like Dursban, Malathion, and Diazinon, and carbamate insecticides (Carbaryl and Propoxur), as well as the latest family of nicotinoids (nicotine derivatives), are all neurotoxins. These chemicals work by interrupting the electrochemical processes that nerves use to communicate with muscles and with other nerves. A key chemical in communication between neurons is called a neurotransmitter—acetylcholine is the neurotransmitter involved in muscle contractions. Acetylcholine (produced by the body) is used to "fire" the neuron, and then is inhibited by an enzyme called cholinesterase. In a healthy nervous system, acetylcholine passes a signal (fires) between one neuron and another, or between a nerve and a muscle receptor. The enzyme cholinesterase is released and binds to the acetylcholine, allowing the nerves to rest. Cholinesterase, however, is not unique to insects--it is also a component of the canine nervous system. (The enteric nervous system uses the major neurotransmitters, like acetylcholine, serotonin, Motilin.)


The nicotinoid insecticides like imidacloprid, activate the nicotinic acetylcholine receptor, but do so steadily, since they are insensitive to the action of cholinesterase. This persistent activation leads to an over stimulation of cholinergic synapses, and results in hyper-excitation, convulsions, paralysis, and the death of the insect. The organophosphate group of insecticides inactivates cholinesterase to prevent the degradation of the neurotransmitter acetylcholine; this results in a constant flow of acetylcholine at the synapse. The carbamate insecticides mimic acetylcholine--as the acetylcholine builds up, the muscles of the body become over-stimulated, leading to paralysis and death.


Neurotoxic pesticides are highly toxic to mammals with a chemical characteristic that leads them to dissipate very slowly once introduced to the body. They are used directly on dogs, as well as in their environment. The assumption is that small amounts are sufficient to kill an insect but will not harm a dog, but is it possible to really limit exposure? These chemicals are now ubiquitous in our environment. For example, the Environmental Protection Agency estimates that 60 million pounds of organophosphate pesticides are applied within the United States every year. Chlorpyrifos is the most widely used insecticide in the Chesapeake Bay district. Recent studies show that this organophosphate chemical is consistently present in the air, rain and surface waters of the Chesapeake Bay region, suggesting a long environmental half-life.

Perhaps more frightening than knowing these chemicals exist in our 
environment, is knowing they exist and bioaccumulate inside the 
bodies of our children and our dogs. 

             •  A study to measure the organophosphorus
                pesticide exposure among children living in
                two Seattle metropolitan area
that 99% of the children had
                measurable levels of organophosphate
                pesticide metabolites.

• In Minnesota, the 1997 Children's Pesticide
                Exposure Study looked at urine samples from
                102 children; 93% had pesticide levels higher
                than in recent population-based studies of
                adults in the United States.


Dr. Itoh’s studies involve dogs but his goal is to treat humans with “altered motility gastrointestinal disorders.” Dr. Itoh (together with Dr. S. Omura), discovered that by using a synthetic motilin, he could effectively stimulate the release of motilin in the dog, initiate the contractions, and begin the next phase of digestion (which causes gastric emptying). Eventually, Itoh found that the antibiotic, erythromycin simulated the action of motilin. He was able to isolate the component in erythromycin responsible for the action, which he called EM574, now patented as by Takeda Chemical Industries’ pharmaceutical division.

Many questions remain for future research projects. As with most diseases, prevention when possible may guarantee survival for your Leonberger. Follow the recommendations of Dr. Larry Glickman, and avoid the use of neurotoxic chemicals. These chemicals persist in the residential environment for longer than a year, and they bioaccumulate, meaning the chemicals are taken up and stored in fatty tissue faster than they are broken down (metabolized) or excreted. Most important, because of individual genetic susceptibilities based not only on major histocompatibility complex differences but also on differences in toxin metabolism, lifestyles, and exposure rates, individuals will react differently to the same chemicals.

The three breeds known to comprise the Leonberger: Great
Pyrenees, Saint Bernard and Newfoundland are all in the top ten of breeds that are prone to bloat with some frequency.  Therefore, you must become aware of the symptoms, understand the dangers and plan ahead--just in case!

©  2002 Barbara Bouyet
excerpted and adapted from “Akita-Treasure of Japan, Volume II” 

Last updated 08/01/2017 .
© 2004 All Rights Reserved.


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