Non-dietary risk factors for gastric dilatation-volvulus in large and giant breed dogs

Abstract

Objective —To identify non-dietary risk factors for gastric dilatation-volvulus (GDV) in large breed and giant breed dogs.
Design —Prospective cohort study.
Animals —1,637 dogs ≥ 6 months old of the following breeds: Akita, Bloodhound, Collie, Great Dane, Irish Setter, Irish Wolfhound, Newfoundland, Rottweiler, Saint Bernard, Standard Poodle, and Weimaraner.
Procedure —Owners of dogs that did not have a history of GDV were recruited at dog shows, and the dog's length and height and the depth and width of its thorax and abdomen were measured. Information concerning the dog's medical history, genetic background, personality, and diet was obtained from the owners, and owners were contacted by mail and telephone at approximately 1-year intervals to determine whether dogs had developed GDV or died. Incidence of GDV, calculated on the basis of dogyears at risk for dogs that were or were not exposed to potential risk factors, was used to calculate the relative risk of GDV.
Results and Clinical Relevance —Cumulative incidence of GDV during the study was 6% for large breed and giant breed dogs. Factors significantly associated with an increased risk of GDV were increasing age, having a first-degree relative with a history of GDV, having a faster speed of eating, and having a raised feeding bowl. Approximately 20 and 52% of cases of GDV among the large breed and giant breed dogs, respectively, were attributed to having a raised feed bowl. ( J Am Vet Med Assoc 2000;217:1492–1499)

Full text

1492 Scientific Reports: Original Study JAVMA, Vol 217, No. 10, November 15, 2000
SMALL ANIMALS
G
astric dilatation-volvulus (GDV) in dogs is char-
acterized by rapid accumulation of air in the stom-
ach, malposition of the stomach, increased intragastric
pressure, and often cardiogenic shock. The risk of GDV
can be high in some larger breed dogs. For example, in
a recently completed 5-year prospective study of
> 1,900 show dogs, incidences of GDV in 7 large (23
to 45 kg [50 to 99 lb]) and 4 giant (> 45 kg [> 99 lb])
breeds were 23 and 26 cases/1,000 dog-years at risk,
respectively.
1
On the basis of this incidence, lifetime
risks of developing GDV for large and giant breed dogs
were estimated to be 24 and 22%, respectively.
However, the lifetime risk of developing GDV in the
largest breeds, such as the Great Dane, was 42%. The
high incidence of GDV, together with a case-fatality
rate of approximately 30%, results in GDV being a
leading cause of death for large and giant breed dogs.
Until recently, retrospective studies have been the
primary source of information regarding risk factors
for GDV. These studies indicated that older, large, and
giant purebred dogs with a deep and narrow thorax
that had a first-degree relative with a history of GDV
were at higher risk.
2
Results of retrospective case-con-
trol studies have also suggested that other risk factors
for GDV include faster eating, being fed 1 meal daily,
consuming a diet of dry food only, and having a ner-
vous or fearful temperment.
3
In contrast, dogs reported
by their owners to be happy and easygoing were at
decreased risk of GDV. However, findings from retro-
spective studies must be interpreted with caution,
because information about potential predisposing con-
ditions is collected only after a dog has already suffered
an episode of GDV. Responses from owners can be
biased if they have preconceived ideas about the caus-
es of GDV or if the accuracy of their recall differs sys-
tematically from the accuracy of recall by owners of
nonaffected control dogs.
4
Such bias is best avoided by
querying dog owners about the presence or absence of
risk factors before the onset of GDV and following the
dogs prospectively to determine which ones develop
GDV. A recently completed 5-year prospective study of
incidence of and breed-related risk factors for GDV in
dogs
1
afforded us this opportunity. As a part of that
study, an effort was made to determine the impact of
management factors currently recommended to reduce
the incidence of GDV such as raising the dog’s feed
bowl, restricting exercise before and after eating, and
wetting dry food prior to feeding.
5
The purpose of the
study reported here, therefore, was to identify non-
dietary risk factors for GDV in large and giant breed
dogs. The study was designed to examine potential risk
factors for individual dogs and determine the propor-
tion of cases of GDV attributed to each factor.
Materials and Methods
Recruitment of dogs and owners—Details of the study
procedure have been reported.
1
Eleven national breed clubs,
namely the Akita, Bloodhound, Collie, Great Dane, Irish
Setter, Irish Wolfhound, Newfoundland, Rottweiler, Saint
Bernard, Standard Poodle, and Weimaraner clubs, agreed to
participate in, and partially fund, a prospective study of GDV
at Purdue University. Beginning in June 1994 and ending in
Non-dietary risk factors for gastric
dilatation-volvulus in large and giant breed dogs
Lawrence T. Glickman, VMD, DrPH; Nita W. Glickman, MS, MPH; Diana B. Schellenberg, MS†;
Malathi Raghavan,
DVM, MS; Tana Lee, BA
Objective—To identify non-dietary risk factors for
gastric dilatation-volvulus (GDV) in large breed and
giant breed dogs.
Design—Prospective cohort study.
Animals—1,637 dogs 6 months old of the following
breeds: Akita, Bloodhound, Collie, Great Dane, Irish
Setter, Irish Wolfhound, Newfoundland, Rottweiler,
Saint Bernard, Standard Poodle, and Weimaraner.
Procedure—Owners of dogs that did not have a his-
tory of GDV were recruited at dog shows, and the
dog’s length and height and the depth and width of
its thorax and abdomen were measured. Information
concerning the dog’s medical history, genetic back-
ground, personality, and diet was obtained from the
owners, and owners were contacted by mail and
telephone at approximately 1-year intervals to deter-
mine whether dogs had developed GDV or died.
Incidence of GDV, calculated on the basis of dog-
years at risk for dogs that were or were not exposed
to potential risk factors, was used to calculate the rel-
ative risk of GDV.
Results and Clinical Relevance—Cumulative inci-
dence of GDV during the study was 6% for large
breed and giant breed dogs. Factors significantly
associated with an increased risk of GDV were
increasing age, having a first-degree relative with a
history of GDV, having a faster speed of eating, and
having a raised feeding bowl. Approximately 20 and
52% of cases of GDV among the large breed and
giant breed dogs, respectively, were attributed to
having a raised feed bowl. (
J Am Vet Med Assoc
2000;217:1492–1499)
From the Department of Veterinary Pathobiology (Glickman LT,
Schellenberg, Raghavan, Lee) and the Center for the Human
Animal Bond (Glickman NW), School of Veterinary Medicine,
Purdue University, West Lafayette, IN 47907-1243.
Funded in part by grants from the Morris Animal Foundation, the
American Kennel Club Canine Health Foundation, and the Akita,
Bloodhound, Collie, Great Dane, Irish Setter, Irish Wolfhound,
Newfoundland, Rottweiler, Saint Bernard, Standard Poodle, and
Weimaraner national breed clubs.
†Deceased.
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JAVMA, Vol 217, No. 10, November 15, 2000 Scientific Reports: Original Study 1493
SMALL ANIMALS
March 1997, the investigators visited 27 national or special-
ty dog shows held throughout the United States. Owners
were told of the nature of the study and asked to enroll any
of their dogs that were in attendance. Owners who agreed to
participate were requested to provide their name, address,
and telephone number, the American Kennel Club’s regis-
tered name of their dog, weight of their dog, and information
regarding whether their dog or any of its first-degree relatives
(ie, siblings, offspring, and parents) had ever had GDV.
Owners also gave written permission allowing the investiga-
tors to contact them periodically by telephone or mail.
Confidentiality of all information provided by owners was
emphasized. Dogs were measured at the show using a stan-
dardized protocol. These measurements included length
(humeral deltoid tuberosity to ischium), height at the top of
the withers, depth and width of the thorax at the level of the
costal arch, and depth and width of the abdomen at the level
of the umbilicus. Body condition (eg, thin, lean, optimum,
overweight, obese) was also recorded. Procedures used in
this study were approved by the Committee on the Use of
Human Research Subjects and the Animal Care and Use
Committee of Purdue University.
Data collection—Within 30 days after enrollment, own-
ers were mailed an 8-page questionnaire designed to gather
information concerning their dogs’ current vital status and
history of GDV. A detailed description of the questionnaire
and follow-up procedures has been published.
1
Dogs that had
developed GDV prior to enrollment in the study were
excluded.
Data management and analysis—Data were analyzed
with a statistical software program.
a
Incidence of GDV and
associated 95% confidence limits (CL) were calculated for
the 4 giant (body weight > 45 kg [> 99lb]) breeds combined
(Great Dane, Irish Wolfhound, Newfoundland, Saint
Bernard) and for the 7 large (23 to 45 kg [50 to 99 lb]) breeds
combined (Akita, Bloodhound, Collie, Irish Setter,
Rottweiler, Standard Poodle, Weimaraner), as described.
1
This same approach was used to calculate incidence of GDV
for dogs that had or had not been exposed to potential host-
related, morphometric, personality or temperament, and
environmental or management risk factors for GDV. The rel-
ative risk and its 95% CL and P value were calculated for each
potential risk factor (univariate analysis) by dividing the
incidence of GDV among dogs that had been exposed to the
risk factor by the incidence among dogs that had not been
exposed. The population attributable risk for potentially
modifiable risk factors for GDV was calculated on the basis
of the prevalence of these risk factors and their relative risk.
6
Risk factors associated with GDV in univariate analyses
at P < 0.2 were included in a multivariate Cox proportional
hazards regression analysis.
7
Separate hazards models were
created for host, morphometric, personality or temperament,
and environmental or management factors. Risk factors for
which the P value was < 0.1 were entered into a final pro-
portional hazards model for large and giant breed dogs com-
bined. Risk factors for GDV in the final model were consid-
ered to be significant if P was < 0.05. Because there were dif-
ferences among the 11 breeds in regard to size and body
shape and between males and females within a breed, mor-
phometric measurements and indices were standardized by
breed and sex for the risk factor analysis. This was done by
calculating the mean and SD for each measurement or index
by breed and sex. Values for each dog were classified as low
(> 1 SD less than the mean), medium (between 1 SD less
than the mean and 1 SD greater than the mean), or high (> 1
SD greater than the mean).
Results
Signalment of dogs enrolled—Owners of 1,991
dogs answered the initial questions at dog shows, but
77 (3.9%) dogs were excluded, because they had a his-
tory of GDV. Of the remaining 1,914 dogs that were
enrolled in the prospective study, vital status informa-
tion was obtained for 1,843 (96.3%) at least once dur-
ing the follow-up period, and the detailed question-
naire was completed for 1,660 (86.7%). Of these 1,660
dogs, 23 (1.4%) were < 6 months old at the time of
enrollment in the study and were excluded from fur-
ther analysis. Thus, 1,637 (82.2%) of the 1,991 dogs
initially enrolled in the study were available for char-
acterization of risk factors for GDV.
The 1,637 dogs included in the study consisted of
96 Akitas, 105 Bloodhounds, 174 Collies, 160 Great
Danes, 231 Irish Setters, 170 Irish Wolfhounds, 262
Newfoundlands, 91 Rottweilers, 112 Standard Poodles,
151 Saint Bernards, and 85 Weimaraners (Table 1).
Median age of all dogs at the time of enrollment in the
study was 2.3 years (range, 0.5 to 14.6 years). There
were 743 (45.4%) males and 894 (54.6%) females.
Eighty-five (11.4%) of the males and 163 (18.2%) of the
Median duration
No. of dogs No. of No. of Median age in years of follow-up in years
Breed enrolled males females (range) (maximum)
Large breed dogs
Akita 96 54 42 2.3 (0.5–10.7) 2.0 (2.5)
Bloodhound 105 40 65 2.0 (0.5–10.9) 2.6 (2.8)
Collie 174 81 93 2.1 (0.5–12.1) 2.9 (2.9)
Irish Setter 231 96 135 3.3 (0.5–13.6) 3.0 (4.8)
Rottweiler 91 36 55 3.0 (0.6–10.3) 2.7 (2.8)
Standard Poodle 112 56 56 2.4 (0.5–14.2) 2.7 (2.8)
Weimaraner 85 35 50 2.2 (0.5–14.6) 2.5 (2.6)
Subtotal 894 398 496 2.4 (0.5–14.6) 2.6 (4.8)
Giant breed dogs
Great Dane 160 63 97 2.1 (0.5–8.0) 3.3 (4.4)
Irish Wolfhound 170 75 95 2.5 (0.5–8.0) 2.8 (2.9)
Newfoundland 262 118 144 2.8 (0.5–12.1) 1.9 (2.0)
Saint Bernard 151 89 62 1.7 (0.5–8.5) 2.1 (2.5)
Subtotal 743 345 398 2.3 (0.5–12.1) 2.0 (4.4)
Total 1,637 743 894 2.3 (0.5–14.6) 2.4 (4.8)
Table 1—Demographics of large breed (23 to 45 kg [50 to 99 lb]) and giant breed ( 45 kg [ 99 lb])
dogs included in a study of non-dietary risk factors for gastric dilatation-volvulus (GDV)
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1494 Scientific Reports: Original Study JAVMA, Vol 217, No. 10, November 15, 2000
SMALL ANIMALS
Large breed dogs Giant breed dogs
Incidence Incidence
No. of of GDV* Relative risk No. of of GDV* Relative risk
Factor dogs (95% CI) (95% CI)
P
value dogs (95% CI) (95% CI)
P
value
Breed size 894 24 (18–30) NA NA 743 27 (19–35) NA NA
Age (y) NA NA
0.5–2.9 19 (9–29) 1.00 NA 9 (1–17) 1.00 NA
3.0–4.9 9 (2–16) 0.50 (0.20–1.26) 0.18 24 (11–37) 2.81 (1.01–7.80).. 0.04
 5.0 42 (28–56) 2.24 (1.18–4.25) 0.01 56 (34–78) 6.52 (2.50–17.04) 0.00
Sex
Male 398 28 (18–38) 1.00 NA 345 26 (14–38) 1.00 NA
Female 496 20 (12–28) 0.73 (0.43–1.24) 0.27 398 28 (17–39) 1.07 (0.59–1.95).. 0.88
Reproductive status
Sexually intact male 356 29 (18–40) 1.00 NA 302 28 (15–41) 1.00 NA
Castrated male 42 19 (–7–45) 0.64 (0.15–2.70) 0.76 43 12 (–12–36) 0.43 (0.06–3.21).. 0.72
Sexually intact female 408 19 (11–27) 1.00 NA 323 25 (13–37) 1.00 NA
Spayed female 88 30 (6–54) 1.60 (0.64–3.97) 0.29 75 43 (11–75) 1.70 (0.71–4.07).. 0.30
Body condition
Thin or lean 51 40 (5–75) 1.72 (0.68–4.31) 0.23 52 48 (10–86) 1.76 (0.74–4.16).. 0.17
Optimum 801 23 (16–30) 1.00 NA 651 27 (18–36) 1.00 NA
Overweight or obese 42 11 (–11–33) 0.46 (0.06–3.36) 0.72 40 0 0.00 0.27
Type of breeding
Inbreeding 42 18 (–7–43) 0.95 (0.22–4.10) 1.00 15 0 0.00 0.62
Line breeding 452 29 (19–39) 1.49 (0.84–2.65) 0.21 399 24 (13–35) 0.73 (0.39–1.34).. 0.35
Outcross 373 19 (10–28) 1.00 NA 293 33 (19–47) 1.00 NA
History of GDV in any
first-degree relative
No 600 17 (10–24) 1.00 NA 500 23 (14–32) 1.00 NA
Yes 210 40 (23–57) 2.33 (1.32–4.11) 0.01 170 41 (22–60) 1.75 (0.94–3.27).. 0.08
History of GDV in any parent
No 615 21 (14–28) 1.00 NA 510 26 (16–36) 1.00 NA
Yes 147 32 (15–49) 1.49 (0.79–2.84) 0.21 135 37 (16–58) 1.40 (0.71–2.75).. 0.35
History of GDV in any sibling
No 591 17 (10–24) 1.00 NA 493 26 (16–36) 1.00 NA
Yes 79 63 (29–97) 3.60 (1.85–7.01) 0.00 46 72 (22–122) 2.81 (1.28–6.19).. 0.02
History of GDV in any offspring
No 348 19 (10–28) 1.00 NA 274 31 (17–45) 1.00 NA
Yes 24 106 (13–199) 5.62 (2.07–15.23) 0.00 17 106 (2–210) 3.45 (1.17–10.20) 0.04
Speed of eating
1–3 159 13 (2–24) 1.00 NA 111 36 (12–60) 1.00 NA
4–6 346 23 (13–33) 1.82 (0.68–4.82) 0.29 273 29 (15–43) 0.79 (0.35–1.77).. 0.53
7–10 379 30 (19–41) 2.36 (0.91–6.12) 0.09 354 22 (12–32) 0.62 (0.27–1.38).. 0.26
Weight of dog at 4 months
Below average 62 18 (–2–38) 0.78 (0.24–2.51) 1.00 44 35 (1–69) 1.34 (0.47–3.80).. 0.55
Approximately average 702 23 (16–30) 1.00 NA 557 26 (17–35) 1.00 NA
Above average 55 31 (1–61) 1.35 (0.48–3.76) 0.55 97 29 (6–52) 1.11 (0.46–2.66).. 0.82
Puppy feeding regimen
Maximize growth 61 13 (–5–31) 0.53 (0.13–2.17) 0.58 30 43 (–6–92) 1.72 (0.52–5.72).. 0.43
Attain average growth 673 25 (18–32) 1.00 NA 456 25 (15–35) 1.00 NA
Slow growth 72 14 (–2–30) 0.55 (0.17–1.78) 0.48 209 31 (15–47) 1.24 (0.64–2.40).. 0.60
Major or chronic problems
during first year of life
Yes 91 16 (0–32) 1.00 NA 93 47 (16–78) 1.00 NA
No 765 25 (18–32) 1.58 (0.57–4.38) 0.52 619 23 (15–31) 0.50 (0.24–1.04).. 0.09
Major or chronic medical problems
after first year of life
Yes 119 25 (8–42) 1.00 NA 102 50 (19–81) 1.00 NA
No 721 23 (16–30) 0.93 (0.44–1.97) 0.84 579 25 (16–34) 0.51 (0.25–1.03).. 0.07
Dog has eructations
Yes 417 22 (13–31) 0.85 (0.50–1.46) 0.59 365 32 (20–44) 1.54 (0.82–2.87).. 0.22
No 473 26 (17–35) 1.00 NA 371 21 (11–31) 1.00 NA
Frequency of eructations
Rarely 169 19 (6–32) 1.00 NA 103 26 (5–47) 1.00 NA
Occasionally 167 22 (8–36) 1.16 (0.45–2.99) 0.81 172 31 (13–49) 1.23 (0.46–3.27).. 0.81
Often 73 27 (3–51) 1.47 (0.48–4.50) 0.55 79 41 (11–71) 1.60 (0.54–4.76).. 0.41
Dog has flatulence
Yes 482 23 (14–32) 0.96 (0.56–1.64) 0.89 356 30 (18–42) 1.35 (0.73–2.49).. 0.36
No 402 24 (15–33) 1.00 NA 376 22 (12–32) 1.00 NA
Frequency of flatulence
Rarely 205 25 (11–39) 1.00 NA 174 23 (8–38) 1.00 NA
Occasionally 197 22 (9–35) 0.91 (0.41–2.03) 0.84 121 36 (14–58) 1.57 (0.64–3.87).. 0.36
Often 72 18 (–2–38) 0.72 (0.21–2.54) 0.78 52 41 (5–77) 1.82 (0.61–5.43).. 0.34
Post-prandial abdominal
distention
Yes 60 26 (1–51) 1.08 (0.39–3.00) 0.79 34 74 (15–133) 3.16 (1.33–7.50).. 0.02
No 815 24 (17–31) 1.00 NA 691 24 (16–32) 1.00 NA
*No. of cases/1,000 dog-years at risk.
CI  Confidence interval. NA  Not applicable. Relative risk of GDV in giant breed vs large breeds dogs was 1.15 (95% CI, 0.77–1.71;
P
 0.54).
Table 2—Univariate analysis of host risk factors for GDV in large breed and giant breed dogs
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SMALL ANIMALS
females were neutered. Median duration of follow-up
for the 1,637 dogs was 2.4 years (maximum, 4.8 years).
Death rate—During the follow-up period, 182
(11.1%) of the 1,637 dogs died (93/894 large breed
dogs [10.4%] and 89/743 giant breed dogs [12.0%]).
Of the 182 dogs that died, 29 (15.9%) died of GDV.
Other common causes of death included cancer (46
dogs) and neurologic diseases (9 dogs). Twenty-four
dogs died of unknown causes. Death rate for the 894
large breed dogs was 41 deaths/1,000 dog-years at risk
(95% CL, 33 to 49 deaths/1,000 dog-years at risk) ver-
sus a rate of 56 deaths/1,000 dog-years at risk (95%
CL, 44 to 68 deaths/1,000 dog-years at risk) for the 743
giant breed dogs (P = 0.05).
Incidence of GDV—Overall, 98 dogs included in
the study developed GDV. We did not detect a significant
(P = 0.54) difference between incidence of GDV among
large breed dogs (24 cases of GDV/1,000 dog-years at
risk; 95% CL, 18 to 30 cases/1,000 dog-years at risk) and
incidence among giant breed dogs (27 cases/1,000 dog-
years at risk; 95% CL, 19 to 35 cases/1,000 dog-years at
risk). During the study, 21 (2.4%) of 894 large breed dogs
and 20 (2.7%) of 743 giant breed dogs had at least 1
episode of GDV for each year of observation. Of the 98
dogs that developed GDV, 29 (30%) died. The cumula-
tive incidence of GDV during the study was 6.0% for the
large breed and giant breed dogs.
Risk factor analysis—In univariate analyses of
potential host risk factors for GDV, increasing age and
a history of GDV in any first-degree relative, or specif-
ically in a sibling or offspring, were associated with an
increased risk of GDV (P < 0.2) in large breed and
giant breed dogs (Table 2). An increased speed of eat-
ing was associated with an increased risk of GDV in
large breed, but not giant breed, dogs. Host factors
associated with an increased risk of GDV in giant
breed, but not large breed, dogs were having a thin or
lean body condition, a history of chronic medical prob-
lems, and postprandial abdominal distention.
Large breed dogs Giant breed dogs
Incidence Incidence
No. of of GDV Relative risk No. of of GDV Relative risk
Factor dogs (95% CI) (95% CI)
P
value dogs (95% CI) (95% CI)
P
value
Height
Low 138 23 (7–39) 0.85 (0.40–1.81) 0.86 101 13 (–2–28) 0.46 (0.14–1.49) 0.26
Medium 619 27 (19–35) 1.00 NA 536 29 (19–39) 1.00 NA
High 130 29 (–1–19) 0.35 (0.11–1.14) 0.07 102 36 (11–61) 1.25 (0.58–2.71) 0.53
Weight
Low 114 13 (0–26) 0.48 (0.17–1.34) 0.17 113 16 (0–32) 0.53 (0.19–1.50) 0.29
Medium 662 27 (19–35) 1.00 NA 529 30 (20–40) 1.00 NA
High 118 14 (0–28) 0.51 (0.19–1.43) 0.23 101 27 (5–49) 0.91 (0.38–2.17) 1.00
Body mass index*
Low 126 15 (2–28) 0.55 (0.22–1.39) 0.25 115 27 (7–47) 1.02 (0.45–2.34) 1.00
Medium 629 27 (19–35) 1.00 NA 509 26 (16–36) 1.00 NA
High 132 16 (2–30) 0.58 (0.23–1.45) 0.33 115 35 (12–58) 1.34 (0.63–2.85) 0.41
Thoracic depth
Low 152 15 (3–27) 0.56 (0.24–1.33) 0.21 107 17 (0–34) 0.58 (0.21–1.64) 0.39
Medium 590 26 (18–34) 1.00 NA 530 29 (19–39) 1.00 NA
High 144 24 (7–41) 0.93 (0.43–1.98) 1.00 98 28 (6–50) 0.98 (0.41–2.33) 1.00
Thoracic width
Low 124 24 (6–42) 1.00 (0.45–2.24) 1.00 132 13 (0–26) 0.43 (0.15–1.22) 0.11
Medium 640 23 (16–30) 1.00 NA 496 31 (20–42) 1.00 NA
High 124 24 (6–42) 1.03 (0.46–2.30) 0.84 108 26 (5–47) 0.85 (0.35–2.02) 0.84
Thoracic depth-to-width ratio
Low 134 29 (11–47) 1.22 (0.61–2.45) 0.57 102 29 (6–52) 1.03 (0.43–2.45) 1.00
Medium 620 23 (16–30) 1.00 NA 520 28 (18–38) 1.00 NA
High 132 19 (4–34) 0.81 (0.34–1.92) 0.84 113 20 (2–38) 0.72 (0.28–1.85) 0.67
Abdominal depth
Low 137 24 (7–41) 1.11 (0.52–2.41) 0.84 117 15 (0–30) 0.54 (0.19–1.52) 0.29
Medium 608 22 (15–29) 1.00 NA 513 28 (18–38) 1.00 NA
High 140 33 (13–53) 1.53 (0.77–3.01) 0.24 106 38 (12–64) 1.34 (0.61–2.91) 0.51
Abdominal width
Low 136 11 (0–22) 0.39 (0.14–1.10) 0.07 120 27 (7–47) 0.85 (0.38–1.92) 0.84
Medium 619 28 (20–36) 1.00 NA 504 31 (21–41) 1.00 NA
High 133 16 (2–30) 0.56 (0.22–1.42) 0.26 112 9 (-3–21) 0.27 (0.07–1.13) 0.08
Abdominal depth-to-width ratio
Low 139 14 (2–26) 0.56 (0.22–1.43) 0.33 106 9 (-3–21) 0.31 (0.07–1.28) 0.11
Medium 603 25 (17–33) 1.00 NA 525 28 (18–38) 1.00 NA
High 143 27 (10–44) 1.09 (0.55–2.20) 0.86 105 43 (15–71) 1.53 (0.73–3.20) 0.28
Thoracic depth-to-abdominal
depth ratio
Low 132 26 (9–43) 1.18 (0.57–2.45) 0.69 109 27 (5–49) 0.99 (0.41–2.38) 1.00
Medium 623 22 (15–29) 1.00 NA 518 28 (18–38) 1.00 NA
High 130 27 (8–46) 1.19 (0.55–2.55) 0.68 108 25 (5–45) 0.92 (0.39–2.21) 1.00
*Body mass index = Weight (kg)/[height (cm)]
2
.
For each factor, the mean and SD were calculated by breed and sex. Values for each dog were then classified as low ( 1 SD less than the mean), medium
(between 1 SD less than the mean and 1 SD greater than the mean), or high ( 1 SD greater than the mean).
See
Table 2 for key.
Table 3—Univariate analysis of morphometric risk factors for GDV in large breed and giant breed dogs
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1496 Scientific Reports: Original Study JAVMA, Vol 217, No. 10, November 15, 2000
SMALL ANIMALS
Morphometric factors associated with a decreased risk
of GDV in large breed dogs were greater height, lower
weight, and lower abdominal width, whereas morpho-
metric factors associated with decreased risk of GDV in
giant breed dogs were lower thoracic width, greater
abdominal width, and a lower abdominal depth-to-
width ratio (Table 3). The only personality or tem-
perament factor associated with an increased risk of
GDV in large breed dogs was aggression to people,
whereas submission to other dogs or to people
decreased the risk of GDV. In the giant breed dogs, a
high activity level and a high level of happiness
decreased the risk of GDV (Table 4). Among the envi-
ronmental and management factors, having a raised
feeding bowl and restricting water intake before and
after eating increased the risk of GDV in large breed
and giant breed dogs (Table 5). In large breed dogs, but
not in giant breed dogs, having a rural residence,
restricting exercise before and after eating, and moist-
ening dry dog food prior to feeding increased the risk
of GDV, whereas attending dog shows decreased the
risk of GDV. In giant breed dogs, but not in large breed
dogs, having an urban residence increased the risk of
GDV.
The final proportional hazards risk model includ-
ed 10 potential risk factors and 1 interaction term
(speed of eating X breed size). Factors significantly (P
< 0.05) associated with an increased risk of GDV,
whether adjusted for the other terms in the model or
not, were increasing age, having a first-degree relative
with a history of GDV, having a faster speed of eating,
and having a raised feed bowl (Table 6). Risks of GDV
for dogs with a first-degree relative with a history of
GDV, compared with dogs that did not have a first-
degree relative with a history of GDV, were increased
89 and 63%, respectively, in the unadjusted and
adjusted risk models. The risk of GDV increased by
approximately 20% with each year of age and by 38%
with each unit increase in speed of eating (speed of
eating was scored on a scale from 1 to 10). However,
the relative risk of GDV associated with speed of eat-
ing could not be directly interpreted because of the
significant interaction between speed of eating and
breed size. Therefore, the relationship between speed
of eating and GDV incidence was examined separate-
ly for large breed and giant breed dogs. A faster speed
of eating increased the risk of GDV in large breed
dogs but decreased the risk of GDV in giant breed
dogs (Fig 1). Factors in the final model not signifi-
cantly associated with risk of GDV included breed
size, thoracic depth-to-width ratio, body condition,
place of residence, whether water intake was restrict-
ed prior to eating, number of meals fed daily, and
activity level of the dog.
Results of the final proportional hazards risk
model were used to calculate the population attribut-
able risk of GDV for significant risk factors that own-
ers could potentially modify. For large breed and giant
breed dogs in the present study, 20.4 and 51.9%,
respectively, of the cases of GDV could be attributed
8
to using a raised feed bowl (Table 7). For the large
breed dogs, 37.8% of the cases of GDV could be attrib-
Large breed dogs Giant breed dogs
Incidence Incidence
No. of of GDV Relative risk No. of of GDV Relative risk
Factor dogs (95% CI) (95% CI)
P
value dogs (95% CI) (95% CI)
P
value
Activity score
1–5 110 32 (11–53) 1.00 NA 157 46 (23–69) 1.00 NA
6–10 779 22 (15–29) 0.69 (0.33–1.41) 0.29 582 22 (14–30) 0.48 (0.26–0.90) 0.042
Excitability score
1–3 290 22 (3–41) 1.00 NA 122 32 (10–54) 1.00 NA
4–10 797 24 (17–31) 1.10 (0.44–2.77) 1.00 612 26 (17–35) 0.81 (0.38–1.76) 0.532
Aggression toward dogs score
1–5 725 23 (16–30) 1.00 NA 640 25 (17–33) 1.00 NA
6–10 164 28 (11–45) 1.23 (0.64–2.39) 0.48 298 39 (14–64) 1.55 (0.75–3.24) 0.282
Aggression toward people score
1–2 784 22 (15–29) 1.00 NA 679 27 (19–35) 1.00 NA
3–10 103 37 (13–61) 1.71 (0.83–3.50) 0.18 261 26 (1–51) 0.96 (0.34–2.70) 1.002
Submission to dogs score
1–5 717 27 (19–35) 1.00 NA 586 26 (17–35) 1.00 NA
6–10 170 14 (3–25) 0.51 (0.22–
1.20) 0.13 151 26 (8–44) 0.99 (0.46–2.13) 1.002
Submission to people score
1–7 665 28 (20–36) 1.00 NA 510 25 (16–34) 1.00 NA
8–10 217 14 (4–24) 0.51 (0.24–1.07) 0.09 225 29 (14–44) 1.14 (0.60–2.16) 0.742
Happiness score
1–7 100 30 (9–51) 1.00 NA 283 70 (30–110) 1.00 NA
8–10 790 23 (16–30) 0.76 (0.36–1.61) 0.52 655 22 (14–30) 0.31 (0.16–0.61) 0.002
Easily upset by strangers or
environmental changes score
1–5 729 24 (17–31) 1.00 NA 591 24 (16–32) 1.00 NA
6–10 161 24 (9–39) 0.99 (0.50–1.98) 1.00 149 37 (16–58) 1.54 (0.79–2.99) 0.252
Fearfulness score
1–4 730 24 (17–31) 1.00 NA 597 26 (17–35) 1.00 NA
5–10 157 25 (10–40) 1.03 (0.52–2.05) 0.86 142 33 (13–53) 1.28 (0.63–2.60) 0.442
Trainability score
1–6 111 25 (6–44) 1.00 NA 279 34 (7–61) 1.00 NA
7–10 777 23 (16–30) 0.93 (0.42–2.05) 0.83 657 26 (18–34) 0.76 (0.32–1.81) 0.472
See
Table 2 for key.
Table 4—Univariate analysis of personality and temperament risk factors for GDV in large breed and giant breed dogs
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JAVMA, Vol 217, No. 10, November 15, 2000 Scientific Reports: Original Study 1497
SMALL ANIMALS
uted to a faster speed of eating. For all dogs, 14.3% of
the cases of GDV could be attributed to having a first-
degree relative with GDV. This factor was included in
calculations of attributable risk, because although a
history of GDV in a first-degree relative is not a mod-
ifiable risk factor (ie, it can’t be changed), information
about this risk factor can be used to influence breed-
ing decisions.
Large breed dogs Giant breed dogs
Incidence Incidence
No. of of GDV Relative risk No. of of GDV Relative risk
Factor dogs (95% CI) (95% CI)
P
value dogs (95% CI) (95% CI)
P
value
Place of residence
Urban 380 11 (-4–26) 0.55 (0.13–2.38) 0.563352 45 (6–84) 2.15 (0.75–6.20) 0.18
Suburban 386 20 (11–29) 1.00 NA 245 21 (9–33) 1.00 NA
Rural 420 30 (20–40) 1.56 (0.89–2.74) 0.133 439 27 (17–37) 1.32 (0.65–2.67) 0.50
Regularly attended shows
Yes 796 22 (15–29) 0.58 (0.29–1.16) 0.133 673 26 (18–34) 0.71 (0.30–1.68) 0.45
No 398 38 (14–62) 1.00 NA 370 37 (7–67) 1.00 NA
Person accompanying dog to shows
Owner only 605 22 (15–29) 1.00 NA 596 26 (17–35) 1.00 NA
Handler only 344 39 (-9–27) 0.40 (0.05–2.90) 0.513318 0 0 1.00
Owner and handler 126 24 (6–42) 1.06 (0.47–2.39) 0.833346 28 (–4–60) 1.09 (0.33–3.55) 0.76
Number of dog shows during typical year
 10 335 23 (13–33) 1.00 NA 388 26 (15–37) 1.00 NA
10–19 208 27 (13–41) 1.18 (0.59–2.35) 0.723 170 19 (5–33) 0.72 (0.31–1.69) 0.55
 20 253 17 (7–27) 0.71 (0.34–1.50) 0.463 115 36 (14–58) 1.37 (0.64–2.90) 0.41
Prophylactic gastropexy done
Yes 312 28 (-27–83) 1.18 (0.16–8.51) 0.583310 0 0.00 1.00
No 874 24 (18–30) 1.00 NA 716 28 (20–36) 1.00 NA
Preventive medications or
supplements to prevent GDV
Yes 355 36 (4–68) 1.59 (0.63–3.99) 0.383326 50 (-7–107) 1.91 (0.59–6.17) 0.22
No 827 23 (16–30) 1.00 NA 703 26 (18–34) 1.00 NA
Food given ad libitum
Yes 335 13 (-12–38) 0.52 (0.07–3.74) 1.003316 55 (-21–131) 2.10 (0.51–8.68) 0.26
No 857 24 (18–30) 1.00 NA 726 26 (18–34) 1.00 NA
Number of meals daily
1 159 18 (5–31) 0.68 (0.31–1.50) 0.483396 48 (17–79) 2.06 (0.98–4.32) 0.09
2 684 26 (18–34) 1.00 NA 613 23 (15–31) 1.00 NA
 3 349 39 (-9–27) 0.34 (0.05–2.44) 0.373333 39 (-5–83) 1.68 (0.51–5.48) 0.43
Feed bowl raised
Yes 264 40 (24–56) 2.17 (1.27–3.71) 0.013 401 34 (22–46) 1.99 (1.00–3.95) 0.05
No 625 18 (12–24) 1.00 NA 341 17 (7–27) 1.00 NA
Height of feed bowl
Not raised 625 18 (12–24) 1.00 NA 341 17 (7–27) 1.00 NA
 1 foot 105 56 (26–86) 3.06 (1.60–5.87) 0.002 360 15 (-6–36) 0.89 (0.20–4.03) 1.00
 1 foot 144 29 (-11–47) 1.59 (0.78–3.24) 0.213 324 39 (25–53) 2.29 (1.15–4.58) 0.02
Exercise restricted before and
after eating
Yes 600 27 (19–35) 1.62 (0.85–3.07) 0.153 486 26 (16–36) 0.94 (0.50–1.76) 0.87
No 289 17 (7–27) 1.00 NA 253 28 (14–42) 1.00 NA
Water intake restricted before and
after eating
Yes 123 47 (23–71) 2.31 (1.27–4.19) 0.013387 48 (18–78) 2.02 (1.00–4.10) 0.07
No 766 20 (14–26) 1.00 NA 652 24 (16–32) 1.00 NA
Dry food moistened
Yes 597 29 (21–37) 2.80 (1.26–6.20) 0.013 461 27 (17–37) 0.96 (0.51–1.81) 0.87
No 271 11 (3–19) 1.00 NA 258 28 (14–42) 1.00 NA
See
Table 2 for key.
Table 5—Univariate analysis of environmental and management risk factors for GDV in large breed and giant breed dogs
Unadjusted Adjusted
Factor RR 95% CI
P
value RR 95% CI
P
value
Age (y) 1.17 1.09–1.26 0.001 1.20 1.11–1.301 0.001
Size (giant vs large) 1.27 0.80–1.80 0.361 2.97 0.93–9.451 0.061
First-degree relative with GDV 1.89 1.25–2.89 0.003 1.63 1.06–2.521 0.031
(yes vs no)
Speed of eating score 1.05 0.96–1.13 0.011 1.38 1.06–1.801 0.021
Speed of eating  size interaction 0.81 0.68–0.96 0.021 0.82 10.6–90.98 0.031
Feed bowl raised (yes vs no) 1.96 1.32–2.96 0.001 2.10 1.34–3.301 0.001
RR  Relative risk (incidence of GDV among dogs that had been exposed to the factor of interest divided by incidence
among dogs that had not been exposed). CI  Confidence interval.
Table 6—Proportional hazards model for the risk of GDV in large breed and giant breed dogs
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1498 Scientific Reports: Original Study JAVMA, Vol 217, No. 10, November 15, 2000
SMALL ANIMALS
Discussion
Results of the present study confirmed that various
factors suspected to be risk factors for GDV in large
breed and giant breed dogs were indeed associated
with development of the condition. This included
increasing age and having a first-degree relative with a
history of GDV. It has been suggested that increasing
age is associated with stretching of the ligaments that
support the stomach, which facilitates volvulus when
the stomach is weighted with food.
9
Similarly, a deeper
and narrower thorax is thought to change the anatom-
ic relationship between the stomach and esophagus
such that the dog’s ability to eructate is impaired.
5
In
the present study, however, although the risk of GDV
increased as the thoracic depth-to-width ratio
increased, this relationship was not significant. A
genetic predisposition to GDV may operate through
inheritance of a particular body shape, personality, or
temperament that predisposes to GDV. As in a previous
study,
3
giant breed dogs in the present study reported
by their owners to be happier or to have a higher activ-
ity level were found to be at reduced risk of GDV in
univariate analyses, but no association was apparent in
multivariate analyses between a particular tempera-
ment or personality profile and risk of GDV. A faster
speed of eating was also confirmed to be a risk factor
for GDV, as in a previous study,
3
but only for large
breed dogs. Why speed of eating would be a risk factor
for large breed, but not giant breed, dogs was not deter-
mined. It suggests, however, that recommendations to
prevent GDV should differ depending on the size of the
dog.
Numerous recommendations for preventing GDV
in dogs have been published in veterinary textbooks
5
and lay magazines
10
and appear in literature from dog
food companies
11
and on the Internet. These recom-
mendations typically include the following: feed sever-
al small meals daily, avoid exercise or excessive water
consumption immediately before or after eating, slow
the speed of eating, moisten dry food prior to feeding,
and raise the level of the feed bowl to reduce air intake.
However, none of these recommendations have been
based on sound scientific evidence, and their efficacy
has never been formally evaluated. One textbook
12
rec-
ommends that long-term management of dogs suscep-
tible to GDV should include frequent feeding to mini-
mize gastric distention, reduction of postprandial exer-
cise, and avoidance of short-term consumption of large
volumes of water. However, in the present study, feed-
ing fewer meals per day, restricting exercise or water
intake immediately before or after eating, and raising
the feed bowl were not associated with a decreased risk
of GDV in the multivariate analysis. In addition, in
univariate analyses, many of the recommendations
commonly made to prevent GDV, such as raising the
food bowl, moistening dry food prior to feeding, and
restricting water intake before and after feeding, were
associated with a significantly increased risk of GDV.
Most likely, however, many of these factors were sig-
nificant only because of confounding. For example,
owners of dogs that had a first-degree relative with
GDV were more likely to restrict water and exercise
before and after feeding than owners of dogs that did
not have a first-degree relative with GDV. Thus, when
these potential risk factors were included in a multi-
variate model that also included whether there was a
history of GDV in a first-degree relative, they were no
longer associated with an increased risk of GDV.
However, even in the multivariate analysis, raising the
feed bowl appeared to significantly increase, and not
decrease, the risk of GDV. One can question, therefore,
whether in large breed and giant breed dogs raising the
feed bowl might actually increase the amount of air
ingested while eating.
In a previous study,
3
a variety of stressful events,
including being boarded, having a pet sitter in the
house, exercising excessively, visiting a veterinarian,
traveling, having strangers in the home, or changing
residence, occurred more frequently during the 8
hours preceding an acute episode of GDV in affected
dogs than during a comparable time period in breed-
and age-matched control dogs. In the present study,
however, no attempt was made to determine whether
an episode of stress preceded development of GDV,
because the focus was on predisposing factors rather
than precipitating events.
Many dog owners in the present study reported
attempting to prevent GDV by giving their dogs med-
ications to reduce gas formation or to increase gastric
motility; however, these efforts did not appear to
reduce the incidence of GDV. This may be explained by
the fact that owners of dogs that were at higher risk
because they had a first-degree relative with GDV were
Prevalence of Population AR
Factor factor (%) RR of GDV (%)
Feed bowl raised
Large breed 30 2.17 20.4
Giant breed 54 1.99 51.9
Fast speed of eating
(score 7–10)
Large breed 43 2.36 37.8
First-degree relative 26 1.63 14.3
with GDV
Table 7—Population attributable risks (AR) for potentially modifi-
able risk factors for GDV in large breed and giant breed dogs
Figure 1—Incidence (No. of cases/1,000 dog-years at risk) of
GDV in 884 purebred large breed dogs (solid line) and 738 pure-
bred giant breed dogs (dashed line) as a function of speed of
eating (speed of eating was scored on a scale from 1 to 10).
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JAVMA, Vol 217, No. 10, November 15, 2000 Scientific Reports: Original Study 1499
SMALL ANIMALS
more likely to use medications in an attempt to prevent
GDV. Only 22 owners in the study reported having had
a prophylactic gastropexy performed on their dog, and
1 of these dogs subsequently developed GDV. On the
basis of these small numbers, prophylactic gastropexy
was not associated with a significantly decreased risk
of GDV. However, a previous study
13
found that follow-
ing an acute episode of GDV, the rate of recurrence of
GDV for dogs that had a gastropexy was 4.3%, com-
pared with a rate of 54.5% for dogs that did not under-
go gastropexy.It seems likely, therefore, that gastropexy
might be effective in preventing a first episode of GDV
in genetically predisposed dogs.
Most breeds of dogs included in the present study
were reported anecdotally or found in retrospective
studies
14
to be at a significantly higher risk of GDV.
Owners of such dogs frequently seek a veterinarian’s
advice on how to reduce their dog’s risk of GDV. On the
basis of findings of the present study, the strongest rec-
ommendation to prevent GDV should be to not breed
a dog that has a first-degree relative that has had GDV.
Results of this study suggest that the incidence of GDV
could be reduced by approximately 60%, and there
may be 14% fewer cases in the population if such
advice were followed. However, owners may not be
familiar with the medical history of the relatives of
their dog. Also, because the incidence of GDV increas-
es with age and the typical age at the time of the first
episode of GDV is 10 to 12 years,
1,14
some first-degree
relatives may appear healthy at the time a breeding
decision is required but still develop GDV later in life.
Nonetheless, not breeding dogs with first-degree rela-
tives that have had GDV should reduce the prevalence
of this disease within a breed. On the other hand, at
this time, there seems to be no advantage to restricting
water intake or exercise before or after eating. Slowing
a dog’s speed of eating should be effective in prevent-
ing GDV in large breed dogs, but it appears contraindi-
cated in giant breed dogs. Raising the dog’s feed bowl
should not be done for either large breed or giant breed
dogs. Finally, owners of dogs at the highest risk of
GDV, such as Bloodhounds and Great Danes,
1
should
discuss with their veterinarian having a prophylactic
gastropexy performed at the time of surgical neutering
of their dog. There is no scientific evidence indicating
that gastropexy will prevent a first occurrence of GDV;
however, gastropexy has been shown to prevent a
recurrence of GDV following an acute episode.
13
Owners of high-risk dogs often seek information
concerning diet or feeding changes that might reduce
the risk of GDV. In previous studies, it has been shown
that dogs fed only dry dog food
3
or foods containing
particles < 30 mm in diameter
15
were at increased risk
of developing GDV. However, no specific food types or
ingredients have yet been implicated in the pathogene-
sis of GDV. Detailed dietary information was collected
as part of the prospective study of which the present
study represents a portion. Findings of the dietary
analysis will be the subject of a later report.
a
Proc Univariate, Proc Phreg, SAS Institute, Cary, NC.
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