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The Big
“B”----BLOAT
by Laura Barmore
To me BLOAT was something other people’s dogs got, and quite frankly I wasn’t sure how it
could occur if the other people were taking what I thought were
all the right precautions: moistening their dog’s food, elevating the
food bowls, not allowing their dogs to drink a lot of water right
before or after their meal and never allowing their dogs to have any
strenuous activity before or after eating.
It seemed at each Search & Rescue
seminar and training session I attended there was a lecture given on
GDV and how to recognize it. I had even taken some training on how I
would treat gastric bloat in the field if I was out on a search miles
from help. Not that I really felt I could put a needle in my dog’s
side and feel comfortable releasing the terrible gas that was causing
the problem. But I knew it would be an emergency, a truly life and
death situation if one of my dogs were to get it. Any time wasted
before I could get to a vet would be my worst enemy. The truth is,
they say that up to 40 percent of GDV victims die for lack of
emergency veterinary care within six to 12 hours following its onset.
So this past February evening
when I saw my 10 year old black Lab, Cally, walking towards me
obviously in great pain and with a distended stomach I knew we were in
trouble. But my mind kept replaying the events of what transpired just
fifteen minutes earlier- Cally happily coming down the stone pathway
greeting me with her smile and wagging tail as she knew it was feeding
time. She had spent the previous two hours lying out in the gardens
enjoying an unusually sunny February afternoon. She hadn’t been doing
anything strenuous or active.
She had made a bee-line to her
kennel and eagerly gone on in. Then I shut the gate and gave her, her
usual dinner. I could hear her gulping it down as I turned to go feed
the rest of the gang. Cally has always been a vivacious eater, ever
since I got her some three years ago. We had even gotten to the point
of putting a tennis ball or round toy in her bowl to try to slow her
eating down so she would have to eat around it. She was generally fed
first as her tension and excitement would grow if she knew someone was
eating before her. After dinner, we tended to walk her after everyone
else for her last potty for the night because if the others were out
of their runs, she’d just go in each run and lick their bowls. You’d
think we were starving this dog, but she was a healthy happy sweet
black Lab.
Miraculously and for the first
time I can ever remember her gate didn’t fully close, allowing Cally
to come find me. But the sight of her coming towards me in such pain
changed my thoughts from flashbacks into reality. I rushed her into
the house but it was clear that even normal movement was difficult and
painful. She was restless and anxious, not able to lay down yet
uncomfortable standing. When I touched her distended abdomen she
winced and grunted in pain. I kept telling my daughter “I think Cally
is bloating, we’ve got a problem!” As I dialed the vet, she repeatedly
tried to vomit with little success.
Thankfully, it was 5:15pm and the
vet’s office was still open. I told them I was pretty sure that Cally
was bloating and I was coming right in and to be ready. This is when
the normal thirty minute drive to the vets gets shaved to seventeen as
you drive 80 mph taking the highway, going through every yellow light.
The vet’s office was ready for us
when we arrived, and had a treatment room available. After giving a physical exam
which revealed an enlarged spleen, the first thing the vet did was to
take an x-ray. This x-ray confirmed my worst fears. She did have
bloat, but we had caught it early and the stomach had only twisted 180
degrees. She would have to have emergency surgery to correct the
stomach and to tack it down to prevent it happening again. We wouldn’t
know if there was any damage to her other organs until after surgery.
The vet was cautiously hopeful but said that there still could be
complications.
Our early detection had kept any
damage happening to her other organs. After a few nights stay at the
clinic, Cally was able to return home on a restricted food and
activity regime. Now four weeks after the bloat episode, the only
evidence of the whole ordeal is her shaved belly and the marks there
where her stitches were. Her spirits are terrific and she has that
same smile and happy face. However, inside me, I’ll always have the
big “B’ on my mind, especially at feeding time.
What is GDV or Bloat?
Gastric dilatation-volvulus (GDV)
or bloat as it is commonly referred to, is the severe expansion or
gastric dilation of the stomach which then twists or rotates (volvulus)
on itself. 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. Not all dogs that have a gas buildup and
resultant dilation develop the more serious and life threatening
volvulus. Roughly twenty five percent of bloat cases are caused by the
gastric dilation. The remaining seventy-five percent are due to
gastric volvulus, when the stomach twists more than 180 degrees on its
long axis.
When the stomach twists,
sphincters that control the opening and closing of the two important
passageways into and out of the stomach are closed off—one leading
from the esophagus to the stomach, and the other leading from the
lower end of the stomach to the small intestine. Once this torsion
occurs, it cuts off the inflow and outflow from the stomach preventing
gases from escaping. Since the stomach gasses cannot get out, they
expand and the pressure causes the abdomen to become distended.
Normally the buildup of gas would be relieved by vomiting or belching,
but because of the torsion this can’t happen.
The Risk
With gastric torsion, the blood
supply is cut off and the dog’s condition begins to deteriorate very
rapidly. If this painful condition is not treated within one to two
hours, it is life-threatening. Digestion ceases, causing the
accumulation of fermenting food and accompanying bacteria in the
stomach. The bacteria cause inflammation of the stomach wall, which
can result in tissue death (necrosis) unless treated promptly. The
bacteria can also pass into the dog’s bloodstream, promoting the
formation of blood clots that may impede blood flow to the heart and
cause the dog to go into shock.
Meanwhile, if the bloating
continues and the oxygen supply to the stomach and nearby organs-
primarily the spleen and pancreas- is not restored quickly, the
stomach may rupture. The suffering dog may die from a combination of
factors: tissue damage, a ruptured stomach, kidney failure,
respiratory insufficiency, cardiac failure and shock. Even dogs that
survive surgery and seem to be recovering often succumb to endotoxic
shock hours and even days after the procedure. It is estimated that
even with treatment, at least 35% of the dogs with gastric dilatation
and volvulus die.
What Causes Bloat
There is not one particular
activity that leads to the development of bloat. It appears that it
occurs as a combination of events. Dr. Larry Glickman, an
epidemiologist at the Purdue University School of Veterinary medicine,
conducted a five year controlled study on canine bloat, beginning in
1994. He followed 1,914 dogs that did not have a prior history of
bloat. Eleven large and giant breeds were represented in the study.
From this study, several risk factors were identified:
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One primary risk factor is that its incidence is
closely correlated to the depth and width of the dog’s chest. The
dogs with the greatest risk of developing bloat have chests that are
deep and narrow. This can be evaluated by measuring the depth and
width of the chest, and then the depth is divided by the width. The
depth-to-width ratio reflects the amount of room there is for
stomach movement in the abdomen, behind the ribcage. The higher the
number, the more room there is for movement. Dogs with more room
have a greater risk of developing bloat.
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Lean dogs were found to be at higher risk than
overweight dogs. It is hypothesized that this is because fat takes
up space in the abdomen. The lack of fat in the abdomen of a lean
dog creates a basic situation similar to that of a dog with a deep
and narrow chest. A lean dog has much more room in the abdomen for
the stomach to move around than a fat dog has.
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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 five.
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First degree relatives of dogs that have bloat
have a 63 percent greater risk of developing bloat themselves.
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Dogs that eat quickly have a 15 percent higher
risk of developing bloat. This may be related to the increased
swallowing of air. (Studies of the stomach gas that occurs in
dilation have shown that it is similar to the composition of normal
room air suggesting that the dilatation occurs as a result of
swallowing air.)
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The raising of the food and water bowls was found
to actually increase risk by 110 percent.
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Fearful, nervous, or aggressive dogs had a much
higher incidence of bloat than dogs perceived by their owners as
having happy temperaments.
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Stress can also be a precipitating factor, and
many dogs bloat after recent kenneling, or a recent long car ride.
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A slightly higher percentage of males than
females developed bloat.
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Several diet-related factors were associated with
a higher incidence of bloat. These include feeding only dry food, or
feeding a single large daily meal. Dogs fed dry foods containing fat
among the first four ingredients had a 170 percent higher risk for
developing bloat. Dogs fed dry foods that were moistened prior to
feeding and that contained citric acid had a 320 percent higher risk
for developing bloat. Conversely, feeding a dry food containing a
rendered meat-and-bone meal decreased risk by 53 percent in
comparison with the overall risk for the dogs in the study. Mixing
table food or canned food into dry food also decreased the risk of
bloat.
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Dogs that have bloated were found to have a much
longer hepatogastric ligament which normally when not stretched
would maintain the stomach’s normal position in the abdomen. As for
feeding one large meal a day, this can weigh down the stomach and
stretch the hepatogastric ligament. This could also explain why
bloat risk increases in older dogs since muscles tend to weaken with
age.
Several popular theories
regarding bloat were not substantiated during the study. They were:
1.
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.
2.
There was no correlation to vaccinations.
3.
There was no correlation to the brand of dog food consumed.
4.
There was no correlation to the timing or volume of water
intake before or after eating.
From the research performed to
date, we can list several factors that, added together, can
characterize the typical dog that develops bloat; a deep and narrow
chest, leanness, a relative that has had a bloat episode, eating
quickly, a dry-food diet, a single, large daily meal, and a fearful,
nervous, or aggressive temperament.
What are the Symptoms
The earliest signs typically
include restlessness, anxiety, pacing and whimpering. The dog will
show no interest in water or food and most likely will have
unproductive retching and vomiting. Salivating or drooling is common.
The dog’s abdomen will become visibly distended and have rapid shallow
breathing. The dog may also begin to drool heavily. If the dog’s
condition continues to deteriorate, especially if volvulus has
occurred, the dog’s gum tissue and other mucous membranes may become
pale, and its heart will beat rapidly At this point the dog may die
within hours unless it receives immediate treatment.
How is GDV Treated?
Approximately 35 percent of dogs that develop bloat die or have to be euthanized. This can be
due to shock, arrhythmia (fatal irregular heart beats), or to rupture
or death of the stomach wall. Studies have shown that 40 percent of
dogs that bloat have some heart arrhythmia during the bloat episode.
Affected dogs usually receive fluids and shock therapy at the time of
treatment in an attempt to control this.
The stomach is decompressed
either by passing a tube through the stomach or if a tube cannot be
passed due to the torsion, inserting a large diameter needle into the
stomach right through the abdominal wall to help relieve the pressure.
After the animal is stabilized, x-rays are taken to determine whether
or not a volvulus has occurred. If it has occurred, then emergency
surgery is required to correct the stomach. The doctor will need to
incise the stomach to dissipate the gas and bring the stomach back to
a reasonable state of size and pressure. If a volvulus is present, the
spleen is also involved and often its blood supply becomes
strangulated. Some dogs may also require removal of a damaged spleen
or a portion of the stomach wall.
When the stomach contents are
emptied through the stomach incision, the stomach wall is finally
sutured closed. If a volvulus is present, the surgeon will reposition
the stomach into its normal anatomical position. Then the stomach tube
is inserted through the mouth into the stomach and additional flushing
and antibiotic administration is done. Before closing the abdominal
incision, the surgeon usually will tack (affix with sutures) the
stomach to the abdominal wall to prevent reoccurrence.
Gastropexy, or ‘tacking’ the
stomach is an important aspect of bloat surgery. Studies have shown
that 76 percent of dogs that do not have a gastropexy will bloat
again; more than half will bloat within three month. Only six percent
of dogs that have had a gastropexy have another bloat episode. Dogs
that have gastric dilation without the volvulus should have a
gastropexy performed as soon as possible to reduce dilation and
volvulus from happening in the future.
Depending on the severity of the
episode, the dog may stay in the hospital several days to be monitored
and treated as needed. Unfortunately, some dogs will die in the
postoperative period from complications. Even with treatment, it is
estimated that at least 35% of the dogs with gastric dilatation and
volvulus die.
How is Bloat Prevented?
Canine bloat, or gastric
dilatation-volvulus (GDV), is the number one cause of death for
several of the large and giant breeds. So how do we prevent it? As
with many disorders, selective breeding is the best prevention. Keep
in mind that dogs do not inherit bloat; they only inherit a
predisposition for the condition. There is no single, major gene that
controls bloat. But because of the genetic link involved with this
condition, 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. Perhaps the best selective tool against bloat is the
chest-depth to chest-width ratio. Dogs that have lower ratios and
whose littermates have not bloated are the best breeding candidates.
In addition, the following
recommendations should be followed:
- Large dogs should
be fed two to three times daily, rather than once a day.
- Dogs should be fed
individually and if possible in a quiet stress-free location.
- Try to discourage
your dog from eating rapidly. Place a tennis ball in the bowl so
that the dog has to eat around it or place the food on a cookie
sheet to make the dog have to fish around for the food.
- Schedule the
feedings so that you are present following the dog’s meals in case
any signs of gastric disturbance appear. Don’t feed the dog just
before you go off to work or turn in for the night.
- Diet changes
should be made gradually over a period of three to five days.
- Owners should be
aware of the early signs of bloat.
- As a preventive
measure, owners may want to consider preemptive gastropexy. The
operation can be done in conjunction with other abdominal surgery,
such as spaying.
- Owners should
develop a good working relationship with their local veterinarian in
case emergency care is needed.
Summary:
There are some emergencies that
you never expect to happen to you and your dogs, but as Lab owners, we
need to be very aware of the risk of bloat. If this painful condition
is not treated within one or two hours, it is life threatening.
Understanding it’s prevention, it’s symptoms, and need for prompt
emergency treatment, will help reduce the risk of mortality if your
Lab develops the big “B”.
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