| Bloat (Gastric Dilatation & Volvulus) Veterinary & Aquatic Services Department, Drs. Foster & Smith, Inc. |
| This site was created by and is maintained by Belinda Winters for BFH Bassets. If you have any questions or comments email belindawinters@bfhbassets.com |
What is bloat?
Bloat is the common term for the very serious medical condition known as gastric dilatation and volvulus
(GDV). The gastric dilatation is one part of the condition and the volvulus or torsion is the second part.
In bloat, due to a number of different and sometimes unknown reasons, the stomach fills up with air and
puts pressure on the other organs and diaphragm. Filled with air, the stomach can easily rotate on itself,
thus pinching off the blood supply. Once this rotation (volvulus) occurs and the blood supply is cut off,
the stomach begins to die and the entire blood supply is disrupted and the animal's condition begins to
deteriorate very rapidly. Not all dogs that have a gas buildup and resultant dilatation develop the more
serious and life threatening volvulus. However, almost all dogs that have a volvulus develop it as a result
of a dilatation. GDV is a very serious and life threatening condition. Even with treatment, as many as
25-30% of dogs with GDV die. Understanding the symptoms, prevention, and need for prompt
treatment will help reduce the risk of mortality if your dog develops this problem.
What breeds are more susceptible?
There is a definite link between the likelihood of occurrence of GDV and the breed and build of the dog.
GDV is much more likely to occur in large, deep-chested breeds. The problem can occur in small dogs,
but only rarely. The University of Purdue recently conducted a study of hundreds of dogs that had
developed GDV, and they calculated a ratio of likelihood of a particular breed developing the problem as
compared to a mixed breed dog. For example, using the GDV risk ratio a Great Dane is 41.4 times more
likely to develop GDV than a mixed breed dog.
Breed GDV Risk Ratio Risk Rank
Great Dane 41.4 1
Saint Bernard 21.8 2
Weimaraner 19.3 3
Irish Setter 14.2 4
Gordon Setter 12.3 5
Standard Poodle 8.8 6
Basset Hound 5.9 7
Doberman Pinscher 5.5 8
Old English Sheepdog 4.8 9
German Shorthaired Pointer 4.6 10
Newfoundland 4.4 11
German Shepherd 4.2 12
Airedale Terrier 4.1 13
Alaskan Malamute 4.1 14
Chesapeake Bay Retriever 3.7 15
Boxer 3.7 16
Collie 2.8 17
Labrador Retriever 2 18
English Springer Spaniel 2 19
Samoyed 1.6 20
Dachshund 1.6 21
Golden Retriever 1.2 22
Rottweiler 1.1 23
Mixed 1.0 24
Miniature Poodle 0.3 25
Is there a genetic link?
In addition to breed predilection, there appears to be a genetic link to this disease. The incidence is
closely correlated to the depth and width of the dog's chest. Several different genes from the parents
determine these traits. If both parents have particularly deep chests, then it is highly likely that their
offspring will have a deep chest and the resulting problems that may go with it. This is why in particular
breeds we see a higher incidence in certain lines, most likely because of that line's particular chest
conformation.
What causes gastric dilatation and volvulus?
There is not one particular activity that leads to the development of GDV. It appears that it occurs as
a combination of events. Studies of the stomach gas that occurs in dilatation have shown that it is
similar to the composition of normal room air suggesting that the dilatation occurs as a result of
swallowing air. All dogs, and people for that matter, swallow air, but normally we eructate (burp) and
release this air and it is not a problem. For some reason that scientists have not yet determined, these
dogs that develop bloat do not release this swallowed gas. There is currently several studies looking
into what happens physiologically in these dogs that develop GDV. Through previous studies, there are
several different factors that increase the likelihood of developing the disease. They are: being a male,
being underweight, eating only one meal a day, eating at a faster rate, and being a fearful or nervous dog.
What are the symptoms?
The symptoms include restlessness, pacing, rapid onset of abdominal distension, rapid shallow breathing,
and nonproductive vomiting and retching. Profuse salivation may indicate severe pain. If the dog's
condition continues to deteriorate, especially if volvulus has occurred, the dog may go into shock and
become pale, have a weak pulse, and a rapid heart rate. A dog with gastric dilatation without volvulus can
show all of these symptoms, but the more severe symptoms are likely to occur in dogs with both
dilatation and volvulus.
How is gastric dilatation and volvulus treated?
When the dog is presented to the hospital his condition is assessed and depending on the severity of the
condition, one of a number of different treatment protocols are instituted. Usually intravenous
catheters are placed and fluids are administered. Then the stomach is decompressed either by passing
a stomach tube or inserting a large needle into the stomach and releasing the gas. After the animal is
stabilized, x-rays are taken to determine whether or not a volvulus is present. If a volvulus is present,
then surgery is performed to correct the volvulus. The stomach is permanently stitched to the
abdominal wall to prevent reoccurrence and then the animal is monitored and treated, as needed, based
upon the symptoms. Animals that develop just dilatation are at a much greater risk of developing
dilatation and volvulus in the future, and many times the surgery to attach the stomach permanently is
performed to prevent this from happening. Because this surgery is difficult and invariably happens at
night, many veterinarians will decompress the stomach and treat the patient supportingly and refer
them to a specialty practice, or wait until morning when adequate help is available to assist with the
surgery.
Dogs with gastric dilatation and volvulus can develop severe complications including bleeding disorders,
heart arrhythmias, and peritonitis.
How is gastric dilatation and volvulus prevented?
Despite adopting all of the recommendations listed below, a dog may still develop GDV. Because of the
genetic link involved with this disease, prospective pet owners should question if there is a history of
GDV in the lineage of any puppy that is from a breed listed as high risk. In addition, the following
recommendations should be followed:
Large dogs should be fed two or three times daily, rather than once a day.
Owners of susceptible breeds should be aware of the early symptoms of bloat.
Owners of susceptible breeds should develop a good working relationship with a local
veterinarian in case emergency care is needed.
Water should be available at all times, but should be limited immediately after feeding.
Vigorous exercise, excitement, and stress should be avoided one hour before and two hours
after meals.
Some veterinarians recommend the use of elevated feeders for dogs susceptible to bloat.
Diet changes should be made gradually over a period of three to five days.
Susceptible dogs should be fed individually and, if possible in a quiet location.
Dogs that have survived bloat are at an increased risk for future episodes; therefore
prophylaxis in the form of preventive surgery or medical management should be discussed with
the veterinarian.
Summary
Bloat is a life threatening condition that most commonly affects large-breed, deep-chested dogs over
two years of age. Owners of susceptible breeds should be knowledgeable about the symptoms of the
disease, since early and prompt treatment can greatly improve the outcome. By following the preventive
measures recommended, pet owners can further reduce the likelihood of their pet developing this
devastating problem.
References and Further Reading
Bojrab. Current Techniques in Small Animal Surgery. Williams & Wilkins. Baltimore, MD; 1990.
Veterinary Internal Medicine, Ettinger: Epidemiology of gastric dilatation-volvulus in dogs. Glickman.
Bloat is the common term for the very serious medical condition known as gastric dilatation and volvulus
(GDV). The gastric dilatation is one part of the condition and the volvulus or torsion is the second part.
In bloat, due to a number of different and sometimes unknown reasons, the stomach fills up with air and
puts pressure on the other organs and diaphragm. Filled with air, the stomach can easily rotate on itself,
thus pinching off the blood supply. Once this rotation (volvulus) occurs and the blood supply is cut off,
the stomach begins to die and the entire blood supply is disrupted and the animal's condition begins to
deteriorate very rapidly. Not all dogs that have a gas buildup and resultant dilatation develop the more
serious and life threatening volvulus. However, almost all dogs that have a volvulus develop it as a result
of a dilatation. GDV is a very serious and life threatening condition. Even with treatment, as many as
25-30% of dogs with GDV die. Understanding the symptoms, prevention, and need for prompt
treatment will help reduce the risk of mortality if your dog develops this problem.
What breeds are more susceptible?
There is a definite link between the likelihood of occurrence of GDV and the breed and build of the dog.
GDV is much more likely to occur in large, deep-chested breeds. The problem can occur in small dogs,
but only rarely. The University of Purdue recently conducted a study of hundreds of dogs that had
developed GDV, and they calculated a ratio of likelihood of a particular breed developing the problem as
compared to a mixed breed dog. For example, using the GDV risk ratio a Great Dane is 41.4 times more
likely to develop GDV than a mixed breed dog.
Breed GDV Risk Ratio Risk Rank
Great Dane 41.4 1
Saint Bernard 21.8 2
Weimaraner 19.3 3
Irish Setter 14.2 4
Gordon Setter 12.3 5
Standard Poodle 8.8 6
Basset Hound 5.9 7
Doberman Pinscher 5.5 8
Old English Sheepdog 4.8 9
German Shorthaired Pointer 4.6 10
Newfoundland 4.4 11
German Shepherd 4.2 12
Airedale Terrier 4.1 13
Alaskan Malamute 4.1 14
Chesapeake Bay Retriever 3.7 15
Boxer 3.7 16
Collie 2.8 17
Labrador Retriever 2 18
English Springer Spaniel 2 19
Samoyed 1.6 20
Dachshund 1.6 21
Golden Retriever 1.2 22
Rottweiler 1.1 23
Mixed 1.0 24
Miniature Poodle 0.3 25
Is there a genetic link?
In addition to breed predilection, there appears to be a genetic link to this disease. The incidence is
closely correlated to the depth and width of the dog's chest. Several different genes from the parents
determine these traits. If both parents have particularly deep chests, then it is highly likely that their
offspring will have a deep chest and the resulting problems that may go with it. This is why in particular
breeds we see a higher incidence in certain lines, most likely because of that line's particular chest
conformation.
What causes gastric dilatation and volvulus?
There is not one particular activity that leads to the development of GDV. It appears that it occurs as
a combination of events. Studies of the stomach gas that occurs in dilatation have shown that it is
similar to the composition of normal room air suggesting that the dilatation occurs as a result of
swallowing air. All dogs, and people for that matter, swallow air, but normally we eructate (burp) and
release this air and it is not a problem. For some reason that scientists have not yet determined, these
dogs that develop bloat do not release this swallowed gas. There is currently several studies looking
into what happens physiologically in these dogs that develop GDV. Through previous studies, there are
several different factors that increase the likelihood of developing the disease. They are: being a male,
being underweight, eating only one meal a day, eating at a faster rate, and being a fearful or nervous dog.
What are the symptoms?
The symptoms include restlessness, pacing, rapid onset of abdominal distension, rapid shallow breathing,
and nonproductive vomiting and retching. Profuse salivation may indicate severe pain. If the dog's
condition continues to deteriorate, especially if volvulus has occurred, the dog may go into shock and
become pale, have a weak pulse, and a rapid heart rate. A dog with gastric dilatation without volvulus can
show all of these symptoms, but the more severe symptoms are likely to occur in dogs with both
dilatation and volvulus.
How is gastric dilatation and volvulus treated?
When the dog is presented to the hospital his condition is assessed and depending on the severity of the
condition, one of a number of different treatment protocols are instituted. Usually intravenous
catheters are placed and fluids are administered. Then the stomach is decompressed either by passing
a stomach tube or inserting a large needle into the stomach and releasing the gas. After the animal is
stabilized, x-rays are taken to determine whether or not a volvulus is present. If a volvulus is present,
then surgery is performed to correct the volvulus. The stomach is permanently stitched to the
abdominal wall to prevent reoccurrence and then the animal is monitored and treated, as needed, based
upon the symptoms. Animals that develop just dilatation are at a much greater risk of developing
dilatation and volvulus in the future, and many times the surgery to attach the stomach permanently is
performed to prevent this from happening. Because this surgery is difficult and invariably happens at
night, many veterinarians will decompress the stomach and treat the patient supportingly and refer
them to a specialty practice, or wait until morning when adequate help is available to assist with the
surgery.
Dogs with gastric dilatation and volvulus can develop severe complications including bleeding disorders,
heart arrhythmias, and peritonitis.
How is gastric dilatation and volvulus prevented?
Despite adopting all of the recommendations listed below, a dog may still develop GDV. Because of the
genetic link involved with this disease, prospective pet owners should question if there is a history of
GDV in the lineage of any puppy that is from a breed listed as high risk. In addition, the following
recommendations should be followed:
Large dogs should be fed two or three times daily, rather than once a day.
Owners of susceptible breeds should be aware of the early symptoms of bloat.
Owners of susceptible breeds should develop a good working relationship with a local
veterinarian in case emergency care is needed.
Water should be available at all times, but should be limited immediately after feeding.
Vigorous exercise, excitement, and stress should be avoided one hour before and two hours
after meals.
Some veterinarians recommend the use of elevated feeders for dogs susceptible to bloat.
Diet changes should be made gradually over a period of three to five days.
Susceptible dogs should be fed individually and, if possible in a quiet location.
Dogs that have survived bloat are at an increased risk for future episodes; therefore
prophylaxis in the form of preventive surgery or medical management should be discussed with
the veterinarian.
Summary
Bloat is a life threatening condition that most commonly affects large-breed, deep-chested dogs over
two years of age. Owners of susceptible breeds should be knowledgeable about the symptoms of the
disease, since early and prompt treatment can greatly improve the outcome. By following the preventive
measures recommended, pet owners can further reduce the likelihood of their pet developing this
devastating problem.
References and Further Reading
Bojrab. Current Techniques in Small Animal Surgery. Williams & Wilkins. Baltimore, MD; 1990.
Veterinary Internal Medicine, Ettinger: Epidemiology of gastric dilatation-volvulus in dogs. Glickman.
