BLOAT:
Beware of Bloat
Raven was oddly restless that evening. A few hours after eating, the
year-old Briard was unable to comfortably sit or lie down. She nervously
paced the room. "Pacing with a purpose," is how her owner describes it.
From time to time, Raven retched in a futile attempt to vomit.
A knowledgeable dog owner, Gail thought she might be looking at the
early signs of "bloat"-a digestive disorder with the potential to
quickly turn fatal. She called her veterinarian. At the emergency
clinic, he examined the dog, treated her with fluids and observed her
progress. A radiograph (X-ray) showed that her stomach had a twist
(torsion), and Raven was on her way to surgery.
"What's truly frightening is that I could have said, 'It's late. I'll
wait and see how she is in the morning," Gail says. "I'm just thankful I
acted on my best instincts. Otherwise, Raven would have died.
"After this experience, my advice to other dog owners is to be tuned-in
to your dog's normal behavior so you'll recognize when things aren't
right," she says.
What is GDV?
Gastric dilatation-volvulus (GDV), commonly referred to as "bloat" or
"gastric torsion," is a rapidly progressive, life-threatening disorder
of the digestive system. About one-third of affected dogs die as a
result of GDV, and an estimated 30,000 or more dogs succumb to the
condition each year.
"Bloat should always be considered an emergency," says Dr. Elizabeth
Rozanski, a board-certified specialist in emergency medicine and
critical care at Tufts School of Veterinary Medicine in North Grafton,
Mass. "You can't wait. You have to get treatment immediately. "
Bloat occurs when the stomach becomes severely and painfully distended
or expanded (gastric dilatation) due to the accumulation of air, food,
and fluids in the digestive tract. The stomach then frequently twists
over on itself (volvulus), shutting down both the entrance (esophagus)
to and the exit (pylorus) from the stomach. Because of the decreased
blood flow, toxins build up and can destroy the stomach tissue
(necrosis). The pressure can become so great that the stomach ruptures,
resulting in infection of the abdominal cavity (peritonitis).
The twisting also compresses a major vein that carries blood back to
the heart, disrupting normal circulation throughout the body and causing
an irregular heartbeat (cardiac arrhythmia) in about half of the cases.
Other organs, including the liver, spleen, and pancreas, may also be
compromised. Decreased blood flow to the stomach may result in stomach
death (gastric necrosis).
This sequence of physiological changes can escalate very quickly, from
a case of "simple bloat" to a dog's death from GDV within a few hours.
"That's why it's so important to act early," Rozanski says. However, she
suspects that the seriousness of the dog's condition is more directly
impacted by the intensity of the pressure than the duration of the
illness.
What Causes GDV?
No specific cause for GDV has yet been identified. Development of the
disease is thought to be caused by a number of factors, with
disposition, heredity, body type, exercise, stress, and eating habits
each playing a role.
Deep-chested, large and giant-breed dogs are most commonly affected,
often between the ages of 4 and 10, although older dogs are most often
stricken. Gender does not appear to play a role, with males and females
equally susceptible. Average weight is 80 pounds-plus, although much
smaller dogs can be afflicted. Susceptible breeds include, but are not
limited to, the Great Dane, German shepherd, standard poodle,
rottweiler, akita, bloodhound, Irish setter, golden retriever, Irish
wolfhound, Labrador, and Newfoundland.
But, bloat can develop in dogs of any age or breed, purebred or mixed.
GDV is also seen in certain small and medium-breed dogs, such as the
Dachshund, Basset Hound, and Airedale Terrier.
Dog owners need to be aware of the signs of bloat or GDV:
• Anxiety and restlessness
• A rounded, gas-filled stomach
• Unproductive attempts to vomit
• Salivation and whining
• Difficulty breathing
• Rapid heartbeat
You can check your dog's heart rate (normal range for large-breed dogs
is 60-80 beats per minute) by feeling for it on the upper chest, just
behind the arms, or by pressing on the femoral artery, high up on the
inside of either rear leg for the pulse; count the beats or pulses for
10 seconds and multiply by 6 for the per-minute rate.
You can also look for signs of shock by checking your dog's gums for
pallor or by pressing the tip of your finger against a spot and seeing
how quickly the color returns. But don't waste too much time doing your
own diagnosing-GDV requires the attention of a professional.
Treatment is Vital
Before you jump in the car and head for the veterinary clinic, take a
minute to telephone ahead. The clinic staff will then be ready and
waiting for your arrival. Or, after hearing the extent of your dog's
signs, the veterinarian may direct you to a specialty practice or
veterinary school hospital that's better equipped to treat severe bloat.
At the clinic, the veterinarian will examine the dog, palpate its
abdomen, draw a blood sample, and listen to its heart. Although it may
be possible to diagnose dilatation from this exam, the veterinarian will
take a radiograph to determine if there is volvulus. An EKG to evaluate
heart function or other tests also may be needed.
Evaluating the patient for shock is a critical part of the initial
exam. "Dogs that die from GDV frequently die from the effects of
hypovolemic shock caused by the decrease in circulating blood, Rozanski
says.
While the devastating chain of events caused by reduced circulation has
been described already, the signs of shock the veterinarian looks for
include pale gums and other mucous membranes; shallow, rapid breathing;
fast pulse; weakness; cold skin, and even loss of consciousness.
The first line of treatment involves administering intravenous fluids
to reperfuse (restore liquid to) the dog and counteract shock. Treatment
sometimes includes antibiotics and corticosteroids. Next, the
veterinarian may try to decompress the dog's stomach by inserting a tube
down the esophagus and into the stomach. If successful, the gas will
readily escape, and the stomach contents can be suctioned out. However,
if a tube cannot be placed due to a twist or other blockage, Rozanski
says the veterinarian will try to decompress the stomach by inserting a
large-bore needle or a trochar through the dog's side and into the
stomach to relieve the pressure.
While some "simple bloats" can be resolved in this manner, exploratory
surgery offers the only hope of survival for a dog with dilatation and
volvulus.
Surgery and Recovery
Prior to beginning surgery, the veterinarian will again need to
decompress the dog's stomach, which will have refilled with gas and
fluid. If passing a stomach tube or trocharization is unsuccessful this
time, the surgeon may need to perform a gastrotomy, making an incision
into the dog's stomach, to release the pressure and remove some of the
stomach contents before moving ahead with exploratory surgery.
"After evaluating the overall condition of the abdominal cavity, we
untwist the stomach and restore it to its normal position," explains Dr.
Susan L. Mitchell, a surgeon and assistant professor at Tufts. "We
examine the stomach, spleen, and other organs and surgically remove
unhealthy tissue. We also look for tumors and other abnormalities." If
it has been entrapped and without circulation for too long, the spleen
may also need to be removed (splenectomy).
The surgeon will finish by securing the stomach (gastropexy) to the
(right) abdominal wall or other structures so as to prevent a recurrence
of volvulus. According to Dr. Mitchell, surgeons have several options-an
incisional, a belt-loop, or a circumcostal gastropexy-each of which
provides a secure attachment so as to help deter future bouts of GDV.
This procedure is extremely effective. With it (according to the Merck
Veterinary Manual), fewer than 5 percent of patients experience a
recurrence; without it, the recurrence rate is between 60-80 percent.
With some severe cases, the surgeon may remove part of the stomach and
resect it with surgical stapling and hand suturing.
Occasionally, however, the surgeon may discover that the damage caused
by GDV is extensive and irreparable, and he or she may recommend
euthanasia.
When the risk of GDV is especially high (because of the dog's breed,
history of bloat, or close relatives with GDV), a veterinarian may
suggest prophylactic gastropexy. "An owner may want to consider this as
a preventative, especially if the dog is going to be spayed or is having
another surgical procedure," Mitchell suggests.
Even with the best efforts of the veterinarian, surgeon, and staff, GDV
dogs are still at risk during recovery and may require a week or more of
hospitalization. Development of heart arrhythmia-triggered by the
release of toxins into the bloodstream as the stomach untwists-is
particularly common during recovery. Close monitoring (and medication,
if necessary) of the heart rate and rhythm are very important.
"Overall, the outlook is encouraging, and most dogs do well after
surgery," says Rozanski, citing about an 85-percent survival rate for
GDV surgery at Tufts.
Prevention
Because a second occurrence of bloat is even more dangerous, it's
especially important to take preventative measures-without giving in to
gloom. "If you own a susceptible dog, you shouldn't spend all your time
worrying about bloat," says Rozanski. "Just be aware of the potential
for problems, be familiar with your dog's normal behavior, and act
quickly if any signs of GDV develop."
Prevention is by far the best cure for GDVI but even the most attentive
and careful owner may have a dog that bloats. Tufts veterinarians offer
these precautions and suggestions:
• Do not allow your dog to eat rapidly, gulping excess air along with
its food. If you have more than one dog, feed them in separate rooms so
they'll eat more calmly.
• Divide your dog's daily rations into two or three small meals, which
are easier to digest than one large meal. Mix your dog's dry food with
water, so the kibble expands in the bowl and not in the dog's stomach.
Introduce new foods gradually.
• Avoid feeding your dog "people food" or table scraps.
• Do not permit your dog to exercise vigorously within an hour before or
two hours after eating.
• Prevent your dog from drinking large amounts of water soon before or
after eating.
• Be aware of your dog's normal behavior so you'll recognize subtle
changes in its behavior. Be alert to signs of stress when your dog is
boarded, kenneled, hospitalized, travelling, or showing.
• Keep handy the names, addresses, phone numbers, and office hours of
your veterinarian and a nearby emergency clinic.
Copyright Belvoir Publications Inc. Reprinted with permission, Your
Dog, Oct. 1999. For subscription and other information, call
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