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Researchers at Purdue University conducted a five-year
prospective study of gastric dilation-volvulus using
1,991 large dogs [Akita, Bloodhound, Collie, Irish Setter,
Rottweiler, Standard Poodle, Weimaraner] and giant dogs
[Great Dane, Irish Wolfhound, Newfoundland, Saint Bernard].
Results presented here pertain to large dogs [50 and
99 lbs.] only. Risks were calculated based on an average
life span of 10 years. Several papers resulting from
this study were reviewed and are the basis for the information
presented.
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Bloat refers to any of three conditions:
- Acute gastric dilation:
stomach swelling due to gas, fluid or both
- Torsion: the bloated stomach twists abruptly less
than 180? on the long axis
- Volvulus: the bloated stomach twists abruptly more
than 180? on the long axis
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Signs, Symptom & Treatment of Acute Gastric Dilation
[Non-Torsion Bloat]
Excessive salivation and
drooling, extreme restlessness, unsuccessful attempts
to vomit or pass stool, evidence of abdominal pain,
and whining or groaning when you push on the stomach
wall are common symptoms. The veterinarian will insert
a long rubber or plastic stomach tube into the stomach.
If there is a rush of air and the swelling subsides,
there is no torsion and there is almost immediate relief.
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Signs, Symptom & Treatment of Torsion or Volvulus
Symptoms are the same as
for gastric dilation except the distress if more pronounced.
The dog breathes rapidly, has cold and pale mouth membranes
and may even collapse. These shock-like signs are caused
by strangulation of the blood supply to the stomach
and the spleen. IMMEDIATE surgery is the only treatment.
This is a life and death situation.
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Summary of Signs and Symptoms of Gastric Dilation and
Torsion Complex
Excessive salivation and
drooling
Attempts to vomit or pass stool
Extreme restlessness
Evidence of abdominal pain
Distended abdomen
Seeking a hiding place
Rigid [hard] abdomen
Looking at their side
Abdomen painful when touched
Vomiting foamy or liquid material
Arched back
Unproductive vomiting or retching
Praying position [down in front, rear standing]
Aerophagia [frequent swallowing]
Laying down on belly - crouched position
Hypersalivation [drooling heavily]
Curling up in a ball
Drinking excessively
Laying or sitting in an unusual location
Lethargy, weakness
Lack of appetite
Panting, breathing rapidly or heavily
Quiet, any abnormal behavior
Red or white gums [not normal pink]
Preventative gastropexy has been shown to reduce the
risk of recurrence of GDV by about 95% in dogs that
have already had an episode of GDV. It is expected that
the gastropexy will be at least as effective in preventing
a first occurrence. This surgery is often done when
dogs are neutered. Also, a new laparoscopic technique
reduces the severity of the surgery if done at other
times.
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Species Specific Risks
The six dogs with the highest
incidence of bloat were: Great Dane (11.6%), Irish Setter
(6.4%), Bloodhound (5.5%), Akita (4.5%), Standard Poodle
(4.4%) and Weimeraner (4.0%). The average age of dogs
in this study was 3.2 years and the average age of those
that got GDV was 5.5 years.
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Non-nutritional Risk Factors
1. Age > 5
2. Relatively deep & narrow chest [compared with
other dogs]
Formula: X = chest depth / width
[the higher the number, the greater
the risk]
3. First degree relative with history of GDV
4. Relatively fast eater [compared with other dogs]
5. Uses a raised food bowl
To calculate your dog’s lifetime risk, count one
(1) point for each of the applicable risk factors and
then use the table below to determine the percentage
risk of bloat for your dog.
Percentage Risk # Risk Factors
Number risk factors: 0 or 1 = 8%
Number risk factors: 2 or 3 = 24%
Number risk factors: 4 or 5 = 90%
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More Detailed List of Risk Factors
1. Breed: Standard Poodles
are among the breeds with higher-than-average risk
2. Dogs with greatest risk have deep and narrow chests
which results in more room for stomach movement behind
the ribcage
3. Lean dogs have a higher risk than overweight dogs,
perhaps because fat takes up space in the abdomen
4. Risk is higher for older dogs. Risk increases by
20% each year after age 5
5. First degree relatives of dogs that have had bloat
have a 63% greater risk of developing bloat themselves
6. Dogs that eat quickly have a 15% higher risk of developing
bloat, possibly due to an increased swallowing of air
7. Raising the height of food and water bowls increases
risk by 110% [note that this was previously recommended
as a way to prevent bloat]
8. Fearful, nervous or aggressive dogs had a much higher
incidence of bloat than those with “happy”
temperaments
9. Stress can also be a precipitating factor and many
dogs bloat after recent kenneling or a recent long car
ride [note that three dogs in our group that developed
bloat had recently returned from Tahoe - same or previous
day]
10. Males have a slightly higher risk of bloat than
females
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Nutritional/Diet Related Risk Factors in Bloat*
Risk
Factor
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Risk
of GDV |
% GDV Cases |
Feeding only dry
food
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Increased |
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Feeding a single
large daily meal***
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Increased |
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Dry food containing
fat among the first four ingredients
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Increased |
170% -- 30% |
Foods containing
citric acid that were also moistened prior to
feeding
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Increased |
320% -- 32% |
Dry food with a rendered
meat meal + bone among the first four ingredients
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Decreased |
53% |
Mixing table food
or canned food into dry food
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Decreased |
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* Study population: 1991
dogs in the prospective study; 106 dogs that developed
GDV; and 212 dogs randomly selected from the remaining
pool to be the control group.
** There has been a 1500% increase in bloat in the US
in the past 30 years and this has coincided with the
increased feeding of dry dog foods. Bloat rates in susceptible
breeds in Australia and New Zealand are much lower and
these countries are less dependent on dry foods.
*** A single large meal may stretch the hepatogastric
ligament. This ligament has been found to be much longer
in dogs that develop GDV. Chronic stretching of the
ligament may explain the age factor in bloat. |
Popular Theories Not Substantiated
Bloat was not correlated
with:
1. Exercise before or after eating. Most dogs bloated
in the middle of the night with an empty, gas-filled
stomach.
2. Vaccinations
3. Brand of dog food consumed
4. Timing or volume of water intake before or after
eating
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Treatment
Approximately 30 percent
of dogs that develop bloat die or are euthanized due
to shock, arrhythmia (fatal irregular heart beats),
or rupture or death of the stomach wall. Forty percent
of dogs that bloat have some heart arrhythmia during
the bloat episode and this is usually treated with fluids
and shock therapy.
Emergency treatment of bloat begins with decompression,
or alleviating the gas pressure. This can be accomplished
by passing a stomach tube. If a tube cannot be passed
due to torsion, the use of a hypodermic needle through
the side of the abdomen can help relieve the pressure.
If a dog survives decompression but the stomach is still
twisted, emergency surgery is required to straighten
it. Some dogs may also require removal of a damaged
spleen, or a portion of the stomach wall.
Once normal anatomy is re-established, the most important
aspect of bloat surgery is a gastropexy. This procedure
"tacks" or attaches the stomach wall to the
body wall and prevents it from twisting in the future.
Studies have shown that 76 percent of dogs that do not
have a gastroplexy will bloat again and more than half
will bloat again within three months. Only 6 percent
of dogs that have had a gastropexy have another bloat
episode. Dogs that can be stabilized without surgery
should have a gastropexy performed as soon as possible.
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Breeding Recommendations
Only breed dogs with low
chest depth to width ratios and whose littermates have
not bloated. This may lead to a long term decrease in
the occurrence of bloat.
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References
Glickman, L.T., Research
Updates from the Purdue University Prospective Study
of Canine Gastric Dilation-Volvulus {GDV], November
9, 1998
Glickman, L.T., Research Updates from the Purdue University
Prospective Study of Canine Gastric Dilation-Volvulus
{GDV], October 22, 1999
Glickman, L.T., Glickman, N.W., Schellenberg, D.B.,
Raghavan, M. & Lee, T., Non-dietary risk factors
for gastric dilation-volvulus in large and giant breed
dogs. Journal of the American Veterinary Medical Association,
2000; 217(10); 1492-1499
Raghavan, M., Glickman, L.T., Glickman, N.W., and Schellenberg,
D.B., Dietary risk factors for gastric dilatioation-volvulus
(bloat) in 11 large and giant dog breeds: A nested case-control
study; [date unknown]. ABSTRACT only.
Bell, J.S., Risk Factors for Canine Bloat, Presented
at Tufts’ Canine and Feline Breeding and Genetics
Conference, Oct 2-4, 2003 Also published in the Healthy
Dog section of the April, 2003 AKC Gazette. [AN EXCELLENT
SUMMARY ARTICLE]
Greene, S., What We’re Learning About Bloat: A
Review. http://www.mysticalpoodles.com/09.html in 2004
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