BLOAT - GERMAN SHEPHERD DOGUpdate - A Multifactorial Disease in German Shepherd Dogs - Purina Pro Club
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GERMAN SHEPHERD DOG Update
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A NESTLÉ PURINA PUBLICATION DEDICATED TO GERMAN SHEPHERD DOG ENTHUSIASTS VOLUME 19 | FALL 2021
BLOAT
A Multifactorial Disease in
German Shepherd Dogs
FALL 2021
BLOAT IN GERMAN SHEPHERD DOGS
TIED TO GENETICS & ENVIRONMENT
Longtime co-breeders and co-owners On Labor Day weekend in 2014,
of German Shepherd Dogs, Bo Mehra recalls glancing at her 5-year-
Vujovich (Rosewood) of Cannon Falls, old female, “Frannie” (De Paul’s
Minnesota, and Diane Mehra (Black- Francesca v Blackwood) to see her
wood) of Canon City, Colorado, have abdomen distended on both sides.
never forgotten their first dogs that “She looked like a goat,” she says.
developed gastric dilatation-volvulus “Frannie was beautiful and athletic,”
(GDV), or bloat. Mehra says. “She also was sweet,
Vujovich had never previously intelligent, happy, and well-adjusted.
experienced the disorder in a dog Emergency surgery saved her life.
in 1999 when her 4-year-old male, I had a gastropexy done right then to
“It’s important to realize that “Donny” (CH Rosewood’s Adonis Of ensure she would not have a repeat
Anne-Isle TC), bloated. “Donny was a GDV episode. Frannie lived a healthy
most dogs bloat because of magnificent example of the breed,” she life, recently dying at age 12.”
says. “He had outstanding tempera- German Shepherd Dogs are among
their conformation, and the ment and extraordinary movement. nearly 50 large and giant breeds
One night he became quite agitated, susceptible to GDV. The third most
size of the dog is intrinsically and I attributed it to a bitch in season. popular breed in the country based on
By the next morning, his condition 2020 registrations with the American
linked to conformation.” was too far gone to save him.” Kennel Club, the German Shepherd
Elizabeth A. Rozanski, DVM, DACVIM,
DACVECC, associate professor,
Tufts University Cummings School
of Veterinary Medicine
“Donny” (CH Rosewood’s Adonis of Anne-Isle TC) died in 1999 of bloat. Breeder-
owner Bo Vujovich, who had never previously experienced bloat in a dog, today
makes sure her puppy buyers understand the clinical signs of bloat and also en-
courages them to have a prophylacic gastropexy performed early.
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GERMAN SHEPHERD DOG Update
Dog may be the No. 1 breed for bloat
due to the sheer number of cases.
“It is really difficult to predict which
dogs will bloat,” Vujovich says. “If you
breed many dogs and are around
long enough, it’s going to happen.”
Mehra agrees. “Bloat is so common
in our breed. It’s very sad,” she says.
Traditionally, it has been thought
that GDV occurs when the stomach
fills like a balloon with gas, a process
known as gastric dilatation. As bloat
progresses, the gas-filled stomach
twists 180 degrees clockwise on its
side, cutting off an escape for the
gas through the esophagus or duo-
denum. This is gastric dilatation-
volvulus. A profound distension of
the stomach compresses vital blood
vessels and organs in the abdomen
and reduces oxygen to those organs
causing a life-threatening condition
as tissue death and toxins are re-
leased into the bloodstream.
“Evidence today suggests that
torsion, the flipping of the stomach,
may come first when a dog bloats,”
says Elizabeth A. Rozanski, DVM,
DACVIM, DACVECC, associate professor
at the Cummings School of Veterinary
Medicine at Tufts University. “That
twisting likely seals off the escape
of gas produced by fermentation
causing the stomach to swell. As the
gastric pressure increases, critical A bloat survivor, “Frannie” (De Paul’s Francesca v Blackwood) is pictured at age 10
with owner Iris D’Agostino, whom she lived with for the last five years of her life.
blood supplies to both the stomach D’Agostino was gradually losing her vision, and Frannie restored her confidence
and the whole circulation are cut and enabled D’Agostino to become active again.
off sending a dog into shock.”
No single cause is linked to bloat. include a distended abdomen, pale
“A combination of genetic and environ- gums, and a weak, rapid pulse. Shock
mental factors contribute to bloat,” may occur when the vena cava, the
Dr. Rozanski says. “It’s important to large vein carrying deoxygenated
realize that most dogs bloat because blood back into the heart becomes
of their conformation, and the size of blocked from the stomach’s twisting
the dog is intrinsically linked to confor- and distension.
mation. Deep-chested large and giant Emergency surgery to untwist the
breeds are vulnerable to bloat.” stomach and check for dead tissue
An emergency condition, bloat provides the best outcome for dogs
progresses so fast that dogs can die with GDV. Prior to surgery a veterinar-
within two hours of the first clinical ian must stabilize a dog by relieving
signs. As the gas builds in the stom- the pressure from the gas in the
ach, a dog becomes increasingly stomach and treating a dog for
uncomfortable. Owners may notice shock with intravenous fluids. As
their dog pacing, panting, retching with Frannie, gastropexy is always
unsuccessfully, or standing stiffly performed during emergency surgery
with a hunched back. Clinical signs to prevent GDV from recurring.
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FALL 2021
tribute to late morbidity
and mortality. Awareness
of the potential for multiple
organ dysfunction syn-
drome and aggressive
supportive care are
essential to maximize
the chances for a suc-
cessful outcome for
dogs with GDV.”
Without gastropexy,
GDV recurs in 80 per-
cent of affected dogs
compared to recurrence
of less than 5 percent in
dogs with gastropexy.
“Tuffy” (CH Rosewood’s Man Up), the beloved house While prophylactic gas-
A minimally invasive dog of breeder-owner Bo Vujoivich, died of bloat in tropexy may decrease
2019. Time is of an essence when dealing with a dog the prevalence of GDV
procedure, gastropexy is that has bloated and can quickly turn tragic, she says.
in susceptible breeds, it
Gastropexy involves tacking the does not eliminate the risk for mes-
recommended to be done stomach to the right side of the enteric volvulus. Mesenteric volvulus
abdominal wall to prevent future occurs when the small intestine twists
prophylactically at a young shifting or twisting of the stomach. around the mesentery root that
A minimally invasive procedure, provides nutrients to the intestines.
age, particularly in dogs gastropexy is recommended to be Although rare, mesenteric volvulus
done prophylactically at a young is almost always fatal.
having a parent, littermate age, particularly in dogs having a A study published in 2018 found
parent, littermate or half-sibling an inverse relationship between
or half-sibling that has that has bloated. At many clinics, a decreased GDV cases due to pro-
veterinarian performs a gastropexy phylactic gastropexy surgery and
bloated. laparoscopically using two to three increased incidence of mesenteric
incisions and cameras to help guide volvulus. The retrospective study
the procedure. looked at 54 mesenteric volvulus
When dogs die before GDV surgery cases and 157 controls to determine
can be performed, it is primarily due potential risk factors for the disorder
to shock and cardiovascular instabil-
ity. Dr. Rozanski and Claire R. Sharp,
BVMS, MS, DACVECC, formerly of SIGNS OF GASTRIC
Tufts Cummings School of Veteri- DILATATION-VOLVULUS*
nary Medicine and now at Murdoch
University in Australia, looked at • Dry heaving
the systemic effects of GDV. Their • Yellow, stringy mucus with
review, published in 2014 in Topics white foam
in Companion Animal Medicine, sig- • Tight, hard distended abdomen
naled decreased oxygen to tissues • Restless behavior, pacing and/or
caused by cardiovascular dysfunction inability to settle
as setting in motion a systemic state • Weak, rapid pulse
known as multiple organ dysfunction • Panting
syndrome. Dysfunction can affect the • Pale gums
cardiovascular, respiratory, gastrointes- • Standing with hunched back
tinal, coagulation, and renal systems.
Additionally, Dr. Rozanski says, “Other * If your dog exhibits signs of bloat, you
should immediately seek emergency veteri-
organ dysfunction can develop in the nary care. GDV is a life-threatening condition
postoperative period that requires that can quickly become critical.
specific management and can con-
4
GERMAN SHEPHERD DOG Update
in military working dogs treated at similar ages and breeds that had
the Holland Military Working Dog not experienced GDV. The study
Hospital at Lackland Air Force Base from 2014 to 2018 was funded by
in San Antonio. German Shepherd the AKC Canine Health Foundation
Dogs comprise 60 percent of the with support from 35 sponsors,
Department of Defense’s military including the American German
working dogs. Shepherd Dog Charitable Founda-
Predisposing risk factors included tion and the German Shepherd Dog
breed type, specifically German Club of America.
Shepherd Dog, increasing age, and An article of their findings about
history of gastrointestinal disease, genetic susceptibility factors in large
gastropexy or other abdominal and giants breeds, which have a
surgeries. Because GDV had been a lifetime risk for bloat of 3.9 to 36.7
longstanding cause of death or rea- percent, was published in Genes in
son for euthanasia of military work- November 2020. The genome-wide
ing dogs, in 2001 the U.S. military association study (GWAS) of 253
began implementing a prophylactic dogs from 10 breeds included 147
gastropexy policy for all working dogs that had experienced at least
dogs in their early adult years that one GDV episode and 106 healthy
was rolled out over several years. control dogs. Single nucleotide poly-
Comparatively, there were 116 morphism (SNP) array genotyping
cases of GDV from 1990 to 2000
before the policy went into effect,
95 cases from 2001 to 2009, and
11 cases from 2010 to 2016. During
the same timeframe, six incidents
of mesenteric volvulus were re-
ported from 1990 to 2000, 12 cases
from 2001 to 2009, and 48 cases
from 2010 to 2016.
The link between gastropexy and
mesenteric volvulus is unclear, the
authors stressed. Thus, the benefit of
gastropexy in preventing GDV likely
outweighs the risk of the rare con-
dition mesenteric volvulus, they said.
A GENETIC BASIS FOR
BLOAT
Much is not known about what
causes GDV. It is considered a complex,
multifactorial disorder with genetic
and environmental influences. German
Shepherd Dog enthusiasts suspect
that bloat may occur more frequently
in some bloodlines.
As Mehra, who breeds German
Shepherd Dogs under the Blackwood
prefix, says, “We call it the bloat-torsion
pedigree.”
Efforts to better understand the
genetics of bloat prompted research-
ers at Tufts Cummings School of
Veterinary Medicine to compare
DNA samples from purebred dogs
that had bloated with dogs of
5
FALL 2021
Shorthaired Pointers and Great
SUPPORT FOR GASTROINTESTINAL DISEASE RESEARCH Danes.”
Subsequent analysis identified
German Shepherd Dogs are among the 12 additional significant potentially
breeds in which gastric dilatation-volvulus protective SNPs as well as deleteri-
(GDV), or bloat, is most common. The AKC ous SNPs. Notable significant SNPs
Canine Health Foundation aims to learn the were found in these three genes
causes and breed predisposition for bloat involved in gastric tone and motility,
through support of gastrointestinal disease research. The genetics study VHL, NALCN and PRKCZ.
led by researchers at Tufts University that is featured in this article is part “These are potentially important
of CHF’s efforts to fight this potentially fatal disease. clues to the risk factors of bloat,”
Dr. Rozanski says. “Although further
studies are needed to validate the
followed by imputation of common SNPs identified in the study and
genetic variation was performed on their association with GDV suscep-
241 samples to identify GDV-associat- tibility — as well as their potential
ed SNPs and copy number variations. breed associations — the genes in
The 10 breeds represented were: which they are located have nota-
Borzoi (25.6 percent), German ble roles in enteric nervous system
Shepherd Dog (21.9 percent), Great and GI motility.”
Dane (13 percent), Standard Poodle
(9.8 percent), Doberman Pinscher SURVIVAL STATISTICS &
(6 percent), Briard (5.6 percent), FOCUSING ON PREVENTION
Purina and the AKC Canine Labrador Retriever (4.7 percent), Just as GDV is a multifactorial
Golden Retriever (4.7 percent), and disease in terms of its causes, whether
Health Foundation have German Shorthaired Pointer (4.7 a dog survives bloat is also multi-
percent). factorial. Dr. Sharp and Dr. Rozanski
worked together since 1997 Lead investigator Dr. Rozanski along with colleagues looked at the
explains, “We then used whole- hospital records of 498 dogs that
to support canine health genome sequencing (WGS) on bloated from September 2001 to
a subset of 18 GDV dogs and 15 April 2011 to understand why dogs
research to benefit all dogs. healthy controls of the three high- die prior to surgery in an effort to
est represented breeds — Borzoi, account for preoperative nonsurvival.
German Shepherd Dog and Great The dogs were patients at the Foster
Dane. We identified a potentially Hospital for Small Animals at Tufts
protective intergenic SNP, minor Cummings School of Veterinary
allele G, that appears across all Medicine.
breeds and that is particularly “Excluding the 179 dogs that died
important in Collies, German or were euthanized prior to surgery,
6
GERMAN SHEPHERD DOG Update
83.5 percent, or 318 dogs, survived to
go home,” Dr. Rozanski says. “Overall,
about 64 percent of the dogs studied
survived. We found that financial
reasons were a major risk factor in
nonsurvival. Of the 179 nonsurviving
dogs, 149 were euthanized and 30
died. Of those euthanized, 116 were
euthanized prior to surgery without
the intent to treat.”
Although costs vary based on
geographical area and individual
clinic, emergency bloat surgery,
including gastropexy, may range
from $4,000 to $10,000. Prophy-
lactic gastropexy performed on a
nonemergency basis may cost from LOOKING TO REPRINT?
$1,200 to $2,000.
Given the rate of GDV nonsurvival German Shepherd Dog Update
due to nontreatment, efforts at articles may be reprinted provided
disease prevention may be the best the article is used in its entirety
way to improve disease mortality. and in a positive manner. To request
“If you have a bloodline with young Mehra, whose Frannie survived permission to reprint this article,
dogs bloating and multiple littermates bloat, says, “She was the least likely please contact the editor at:
bloating, it is likely an indicator of dog to bloat because she did not Barbara.Fawver@purina.nestle.
risk genes,” Dr. Rozanski says. “You have the body type prone to GDV. com. Reprints should include the
should try to gradually breed away She had very tight ligamenture and following attribution: Used with
from these dogs.” abdominal muscles. She was happy, permission from the German
Environmental triggers can contrib- well-adjusted, and not a nervous or Shepherd Dog Update, Nestlé
ute as well. “In some lines, stressors anxious dog.” Purina PetCare.
such as a stay at a boarding kennel As to her breeding practices, Mehra
can make them more likely to bloat, says, “I choose breeding partners
particularly in dogs that are anxious very carefully. I look for lines with
and nervous,” she says. “If you have longevity and those free of GDV
an anxious German Shepherd Dog, for one or two generations. I also
it may be helpful to avoid stressful am cautious not to ‘throw the baby
situations.” out with the bath water.’ Doing so
Mehra and Vujovich, who each could result in the loss of genetic
has 30 years’ experience breeding diversity.”
German Shepherd Dogs, educate “Bloat just happens,” Vujovich says.
puppy buyers about the signs of “You can have the best practices
GDV and encourage them to have and routines for your dogs and still
prophylactic gastropexy performed come up with one that bloats.”
early. “Most people cannot afford Reflecting on the significance of
emotionally or mentally to lose the genetic work, Dr. Rozanski says,
an animal to GDV,” Vujovich says. “We are years away from figuring
“Gastropexy offers protection this out, but our findings lean toward
against this happening.” support of a role of genetics in dogs
Both breeders ponder the breed’s that bloat. Maybe all German Shep-
vulnerability to GDV. “The abdominal herd Dogs are somewhat genetically
muscles seem to become lax over at risk.” n
time giving the stomach more room
to twist,” Vujovich says.
Purina appreciates the support of
“Bloat was not a health concern
the American German Shepherd
in German Shepherd Dogs until the
Dog Charitable Foundation board
1980s when breeders began pro-
of directors in helping to identify
ducing dogs with a deeper-bodied
topics for the German Shepherd
conformation to achieve an extended
Dog Update.
side gait,” Mehra says.
7
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