Incidence of and survival after mammary tumors in a population of over 80,000 insured female dogs in Sweden from 1995 to 2002

The main objective of this study was to describe the incidence of mammary tumors (MTs) and the survival after MTs, in female dogs between 3 and 10 years of age (insured for veterinary care and with life insurance in a Swedish animal-insurance company) from 1995 to 2002. Measures of incidence are presented crudely, by breed and across age categories and birth cohorts (1991-1998). The survivals until MT diagnosis and after a MT diagnosis were computed. The overall incidence for any MT claim was 111 dogs per 10,000 dog-years at risk (DYAR). The overall MT rate in the 1992 and 1993 birth cohorts was 154 dogs per 10,000 DYAR. The incidence for any MT claim increased with age and varied by breed, from 319 dogs per 10,000 DYAR in the English springer spaniel to 5 dogs per 10,000 DYAR in the rough-haired collie. At the ages 6, 8 and 10 years, 1%, 6% and 13% respectively, of all females had at least one MT claim. The MT mortality was 6 deaths per 10,000 DYAR and increased with age. The overall-case fatality was 6%.     

Bone tumors in a population of 400 000 insured Swedish dogs up to 10 y of age: incidence and survival

The objectives of this study were to describe the incidence of, survival until, and survival after the diagnosis of canine bone tumors by breed, sex, age, and geographic location of residence. Dogs under 10 y old and insured by a Swedish insurance company between 1995 and 2002 were studied. In total, 764 dogs had claims for bone tumors, and the incidence rate was 5.5 cases per 10 000 dog-years at risk (DYAR). At ages 6, 8, and 10 y, the proportions of dogs with bone tumors were 0.13%, 0.30%, and 0.64%. The top 3 breeds at risk were Irish wolfhound, St. Bernard, and leonberger (incidence rates 99, 78, and 53 cases per 10 000 DYAR, respectively). Median survival time after diagnosis was 56 d in the 419 dogs that survived > or = 1 d. With a Cox regression model controlling for breed and age, females were shown to be at decreased risk of bone tumors, with a hazard ratio of 0.71 (99% confidence interval 0.58 to 0.87).     

Diabetes mellitus in a population of 180,000 insured dogs: incidence, survival, and breed distribution

BACKGROUND: Canine diabetes mellitus (DM) is a common endocrinopathy with an unclear etiology. For a better understanding of the underlying mechanisms, there is a need for comprehensive epidemiologic studies. Earlier studies have shown that the risk of disease is higher in certain dog breeds. HYPOTHESIS: Incidence, age of onset, survival and sex proportion of DM vary by breed. ANIMALS: Data from a cohort of 182,087 insured dogs aged 5-12 years accounting for 652,898 dog-years at risk were studied retrospectively. METHODS: Incidence rates by sex, breed, and geography were calculated with exact denominators. Age-specific incidence and survival after 1st DM claim were computed with Cox's regression and Kaplan-Meier survival function. Multivariable survival analysis was performed for the outcome diagnosis of DM with age, sex, and geography tested as fixed effects, previous endocrine or pancreatic diseases tested as time-dependent covariates, and breed tested as a random effect. RESULTS: The mean age at 1st insurance claim for the 860 DM dogs (72% females) was 8.6 years. The incidence of DM was 13 cases per 10,000 dog-years at risk. Australian Terriers, Samoyeds, Swedish Elkhounds, and Swedish Lapphunds were found to have the highest incidence. The proportion of females with DM varied significantly among breeds. Swedish Elkhounds, Beagles, Norwegian Elkhounds, and Border Collies that developed DM were almost exclusively females. The multivariable model showed that breed, previous hyperadrenocorticism, and female sex were risk factors for developing DM. Median survival time was 57 days after 1st claim. Excluding the 223 dogs that died within 1 day, the median survival time was 2 years after 1st claim of DM. CONCLUSION: The significant breed-specific sex and age differences shown in this study indicate that genetic variation could make breeds more or less susceptible to different types of DM.     

Heart disease as a cause of death in insured Swedish dogs younger than 10 years of age

BACKGROUND: Population-based information on disease occurrence is paramount in clinical decision making and in designing preventative measures, but such information is scarce. HYPOTHESIS: The risk of cardiac death is higher in certain breeds and mortality varies by age and sex. DOGS: Dogs that were life insured by an animal insurance company between 1995 and 2002. METHODS: The mortality pattern for heart disease in insured dogs up to 10 years of age was studied. The influences of sex, age, breed, month, and geographic location were investigated by means of incidence rates, proportions, and survival proportions. Cox proportional hazards regression was used to model time to heart disease. RESULTS: 405,376 dogs contributed to a denominator of 1,431,933 dog-years at risk (DYAR) and 3,049 dogs had been assigned a cardiac-related diagnosis as cause of death. The cardiac-related mortality for dogs <10 years of age, was 21.3 deaths per 10,000 DYAR. This mortality in males and females was 27.3 deaths and 15.4 deaths per 10,000 DYAR, respectively. Twelve of 54 breeds had a point estimate above the overall rate. The 3 breeds with the highest point estimates were: Irish Wolfhounds, Cavalier King Charles Spaniels, and Great Danes (rates of 356, 247, and 179 deaths per 10,000 DYAR, respectively). CONCLUSIONS AND CLINICAL IMPORTANCE: Breed, age, and sex affect cardiac mortality in certain breeds of dogs, but no effects of month and geographic location were identified. These findings can assist clinicians in establishing diagnoses, and can assist breeders in defining priorities for preventative measures.     

Incidence of and breed-related risk factors for gastric dilatation-volvulus in dogs

OBJECTIVE: To compare incidence of and breed-related risk factors for gastric dilatation-volvulus (GDV) among 11 dog breeds (Akita, Bloodhound, Collie, Great Dane, Irish Setter, Irish Wolfhound, Newfoundland, Rottweiler, Saint Bernard, Standard Poodle, and Weimaraner). DESIGN: Prospective cohort study. ANIMALS: 1,914 dogs. 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 depth and width of the thorax and abdomen were measured. Information concerning the dogs' medical history, genetic background, personality, and diet was obtained from 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 based on the number of dog-years at risk was calculated for each breed, and breed-related risk factors were identified. RESULTS AND CLINICAL RELEVANCE: Incidence of GDV for the 7 large (23 to 45 kg [50 to 99 lb]) and 4 giant (> 45 kg [> 99 lb]) breeds was 23 and 26 cases/1,000 dog-years at risk, respectively. Of the 105 dogs that developed GDV, 30 (28.6%) died. Incidence of GDV increased with increasing age. Cumulative incidence of GDV was 5.7% for all breeds. The only breed-specific characteristic significantly associated with a decreased incidence of GDV was an owner-perceived personality trait of happiness.     

Mortality in over 350,000 insured Swedish dogs from 1995-2000: I. Breed-, gender-, age- and cause-specific rates

This study presents data on over 350,000 insured Swedish dogs up to 10 years of age contributing to over one million dog-years at risk (DYAR) during 1995-2000. A total of 43,172 dogs died or were euthanised and of these 72% had a claim with a diagnosis for the cause of death. The overall total mortality was 393 deaths per 10,000 DYAR. Mortality rates are calculated for the 10 most common breeds, 10 breeds with high mortality and a group including all other breeds, crudely and for general causes of death. Proportional mortality is presented for several classifications. Five general causes accounted for 62% of the deaths with a diagnosis (i.e. tumour (18%), trauma (17%), locomotor (13%), heart (8%) and neurological (6%)). Mortality rates for the five most common diagnoses within the general causes of death are presented. These detailed statistics on mortality can be used in breed-specific strategies as well as for general health promotion programs. Further details on survival and relative risk by breed and age are presented in the companion paper (Egenvall et al. 2005).     

Canine keratoconjunctivitis sicca: disease trends in a review of 229 cases

OBJECTIVES: To investigate the disease patterns in dogs with keratoconjunctivitis sicca referred to the University of Glasgow Small Animal Hospital. METHODS: A retrospective study of 229 cases was carried out. RESULTS: There were 44 breeds in the study, with four breeds, English cocker spaniels, cavalier King Charles spaniels, West Highland white terriers and shih-tzus, making up 58 per cent of the cases. Among these four breeds, two breed-dependent disease patterns, one chronic and one acute, were identified. English cocker spaniels and West Highland white terriers had a mean age at onset of clinical signs of five years and one month and five years and six months, respectively, with more females affected than males. Clinical signs consisted predominantly of conjunctival hyperaemia and mucopurulent discharge, with a relatively low incidence of ulcerative keratitis. In contrast, cavalier King Charles spaniels and shih-tzus showed a more acute disease pattern with a biphasic age distribution at 0 to less than two years of age, and four to less than six and six to less than eight years of age, respectively, with more males affected than females and a significantly higher incidence of ulcerative keratitis in some cases resulting in corneal perforation. CLINICAL SIGNIFICANCE: The study reveals interbreed differences with respect to sex, age and risk of ulcerative keratitis which have not been detailed previously in a referral population.     

Incidence and breed predilection for dystocia and risk factors for cesarean section in a Swedish population of insured dogs

OBJECTIVES: To estimate the incidence and breed predilection for canine dystocia using data from insurance claims. The risk factors for cesarean section (CS) were assessed for bitches with dystocia. STUDY DESIGN: Retrospective, longitudinal study. SAMPLE POPULATION: Insurance claims records (1995-2002) from a Swedish animal insurance database (Agria), including approximately 200,000 bitches. METHODS: The overall incidence rate of dystocia in insured bitches was calculated by dividing the number of reimbursed dystocia claims with the number of dog years at risk. Subsequently, incidence rates were stratified by breed, region, and habitat. The proportion of bitches with a dystocia claim that had CS were calculated, and risk factors for CS were assessed using a logistic regression model. RESULTS: Between 1995 and 2002, 3894 (2%) of 195,931 Swedish bitches included in the study had a reimbursed insurance claim for dystocia. The overall incidence rate of dystocia was 5.7 cases/ 1000 dog years at risk. Some breeds like the Scottish terrier were at increased risk of dystocia. Among bitches with dystocia, 63.8% were treated by CS. CONCLUSION: Dystocia in the bitch is more common than reported earlier. The risk of developing dystocia varies by breed, and a high percentage (63.8%) of affected bitches undergo CS. Clinical Relevance- Breeders and veterinarians could use this information to better predict which bitches are likely to experience dystocia and/or CS.     

Breed incidence of lymphoma in a UK population of insured dogs

Canine lymphoma is one of the commonest forms of spontaneous canine neoplasia. Improved understanding of the genetic and environmental risk factors for canine lymphoma, including breed differences, may have comparative benefits for the study of non‐Hodgkin's lymphoma in humans. In this study, data from a pet insurance company were used to estimate the incidences of canine lymphoma for pedigree breeds in the UK. Out of a total of 130 684 insured dogs, 103 had a diagnosis of lymphoma recorded. A significant breed effect was found with the boxer, bulldog and bull mastiff breeds, all having a high incidence of lymphoma. The small number of lymphoma cases recorded may have limited our ability to detect other breeds with an elevated risk. Incidence of lymphoma was found to increase with age, peaking at 10 years of age.     

Idiopathic generalized sebaceous gland hyperplasia of the Border terrier: a morphometric study

Skin biopsies from five Border terriers with histologically confirmed idiopathic, generalized sebaceous gland hyperplasia (Group A) were compared morphometrically to those from four unaffected Border terriers (Group B) and the unaffected dogs to biopsies from four other terrier breeds (Group C). Dogs in Group A had significantly higher numbers of sebaceous gland lobules per hair follicle than those in Group B (P = 0.020) but there was no significant difference between Groups B and C. The total sebaceous gland lobular area per hair follicle was significantly higher in dogs in Group A than Group B (P = 0.020) but there were no differences between Groups B and C. There were no significant differences in the size of the individual sebaceous gland lobules. There were no significant differences in the total number of basal or mature sebocytes between Groups A and B but significantly lower numbers of both cell types were seen in Group C compared to Group B. There were significantly more basal sebaceous cells undergoing mitosis in dogs in Group A than Group B (P = 0.017) but no significant difference between Groups B and C. These results indicate that the physical signs of sebaceous gland hyperplasia are caused by an increase in the number of sebaceous gland lobules and total lobular area. Border terriers may be genetically predisposed to the development of idiopathic generalized sebaceous gland hyperplasia compared with other dog breeds but also to sebaceous gland hyperplasia secondary to other dermatopathies.     

Association between radiographic assessment of hip status and subsequent incidence of veterinary care and mortality related to hip dysplasia in insured Swedish dogs

Our objective was to evaluate the association between grading of hip status as assessed by radiographic examination (hip screening) and subsequent incidence of veterinary care and mortality related to hip dysplasia (HD) in five breeds of insured dogs in Sweden. Screening results for hip status from the Swedish Kennel Club and data on veterinary care and mortality from the insurance company Agria were merged based on the registration number of the dog. Dogs of five breeds (Bernese Mountain Dogs, German Shepherds, Golden Retrievers, Labrador Retrievers, and Rottweilers) screened during 1995–2004 and covered by an insurance plan for veterinary care or life at the time of screening were included. The study populations included between 1667 and 10,663 dogs per breed. Breed-specific multivariable Cox proportional-hazards analyses were performed to evaluate the impact of radiographic hip status on time from hip screening to first HD-related veterinary and life claim, respectively. The effects of gender, birth season, and a time-varying covariate of year were also studied. Additional analyses, on the five breeds combined, were performed to investigate the effects of hip status, breed, and the interaction between hip status and breed. The effect of hip status was highly significant (P < 0.001) for both life and veterinary claims related to HD in all five breeds with increased hazard ratio (HR) for deteriorating hip status. Dogs with moderate or severe hip status at screening had a markedly increased hazard of HD-related veterinary care and mortality compared with dogs assessed as free or mild. The time-varying covariate of year showed a significantly higher HR in the last time period for German Shepherds and Labrador Retrievers in the analyses of veterinary claims. In the analyses on all five breeds, German Shepherds had the highest HR for both veterinary care and mortality related to HD, followed by Bernese Mountain Dogs. Golden and Labrador Retrievers had the lowest HR. The effect of hip status on the hazard was the same irrespective of breed. However, as a consequence of differences between breeds in overall risk, the predictive ability of screening results for subsequent incidence of HD-related problems for individual dogs was breed-dependent. Based on the strong association between radiographic hip status and incidence of HD-related veterinary care and mortality, and the previously reported moderate heritability of hip status, we conclude that selection based on screening results for hip status can be expected to reduce the risk of HD-related clinical problems.     

Breed predisposition to congenital alacrima in dogs

Objective  To evaluate the clinical characteristics and breed predisposition of congenital alacrima in dogs.
Animals studied  Dogs with congenital keratoconjunctivitis sicca.
Procedures  A search of the medical records of the University of Tennessee Veterinary Teaching Hospital from 1974–2005 and the University of California–Davis Veterinary Teaching Hospital from 1986–2006 for dogs under 1 year of age with a diagnosis of keratoconjunctivitis sicca (KCS) was performed. These cases were further reviewed for dogs with a Schirmer's tear test I of ≤ 5 mm/min before 6 months of age, with no known causes for KCS, which did not respond to appropriate KCS therapy; these cases were considered to have congenital alacrima. These breeds were compared to all other breeds using the Fisher's exact test with correction for multiple comparisons.
Results  Congenital alacrima was identified in 19 dogs representing 11 breeds and mixed breeds. Yorkshire Terriers and Bedlington Terriers were statistically overrepresented compared to reference populations ( P  < 0.01 and P  = 0.04, respectively).
Conclusions  Yorkshire terriers are significantly at risk for congenital alacrima compared to other breeds. The significance of the increase in congenital alacrima in Bedlington Terriers in this study may not be clinically relevant and may be due to the small total number of dogs of this breed that presented to the both hospitals. Based on the poor response to therapy in humans with congenital alacrima, it may be prudent to offer guarded prognoses for KCS in juvenile Yorkshire terriers.     

ADAMTS17 mutation associated with primary lens luxation is widespread among breeds

Primary lens luxation (PLL) is a well-recognized, painful and potentially blinding inherited ocular condition in dogs. We screened PLL-affected dogs of 30 different breeds, to identify those which carried a previously described c.1473+1 G>A mutation in ADAMTS17 that is associated with PLL in Miniature Bull terriers, Lancashire Heelers, and Jack Russell terriers. This ADAMTS17 mutation was identified in PLL-affected dogs from 14 additional breeds. PLL-affected dogs from some breeds (most notably the Shar pei and the Brittany spaniel) did not carry the G1473+1A ADAMTS17 mutation, indicating they must suffer from a genetically distinct form of the condition. We also estimated the frequency of this ADAMTS17 mutation in some of the breeds. Our findings indicate the mutation segregates in a large number of different breeds of dog, many of which are terriers or breeds with terrier co-ancestry, but some of which have more diverse origins. Our results also indicate that the mutation is present at high frequency within most of the breeds in which it segregates. In the miniature bull terrier breed estimates of mutation frequency ranged from 0.27 to 0.39, corresponding to 7.3-15.2% PLL-affected dogs in this breed. We also identified an increased risk of PLL associated with heterozygosity at ADAMTS17, suggesting that carriers carry a low risk of developing PLL.     

The spatial distribution of atopic dermatitis cases in a population of insured Swedish dogs

Canine atopic dermatitis (CAD) is manifested by pruritus and inflammation of the skin, and most affected dogs have specific IgE against environmental allergens. Our aim was to evaluate whether in Sweden the incidence of CAD varies spatially, and to investigate possible environmental causes of such variation in a longitudinal study of CAD incidence among insured Swedish dogs. The dataset consisted of >220,000 individuals which had been covered by an insurance plan between January 1, 1995 and December 31, 2002. Out of these, 1235 CAD cases were identified and matched to postal-code areas based upon the address of the owner. Environmental risk factors we considered included averages of long-term annual rainfall, and of January and July temperatures. Initial visualization of the incidence rate of CAD (cases/dog-years at risk) expressed as empirical Bayes smoothed spatial rates indicated geographic variation. Moran's I, adjusted for population at risk, revealed significant global clustering. Both the spatial scan statistic and a local indicator of spatial autocorrelation revealed a higher incidence of CAD in the major cities. In a Poisson-regression model (with a spatial covariance structure), the incidence of CAD increased with increasing human population density, increasing average annual rainfall, living in the southern half of Sweden, and having a veterinary dermatologist in the county.     

FC‐24 Risk factors for atopic dermatitis in a Swedish population of insured dogs

Studies into the epidemiology of canine atopic dermatitis (CAD) are in great demand. Estimates of the prevalence and incidence of CAD are commonly based on hospital studies where no reference population is defined. Such studies tend to overestimate the disease frequency due to referral bias and a higher proportion of complicated cases at secondary care centres than in the general population. The aim of this paper was to present better estimates of the incidence of CAD. The Swedish dog population offers unique opportunities to study the epidemiology of CAD due to several characteristics: a large proportion of dogs are purebred, fleas and flea allergies are rare, and a secondary database of disease records is available through an insurance company that covers approximately 30% of all Swedish dogs. By accessing insurance‐claims records for the years 1995–2000, the true incidence rate of CAD was estimated as 10 cases per 10,000 dog years at risk. Univariate analysis showed that the incidence was the same across genders. Additionally, large differences in the risk of being diagnosed with CAD existed among breeds. In this study, breeds with the highest risk were the bull terrier (88 cases/10,000 dog years at risk), Staffordshire bull terrier (58/10,000), West Highland white terrier (51/10,000), Welsh terrier (50/10,000) and boxer (50/10,000). Decreased risk was observed among sighthounds; no cases were recorded among the Borzoi, Saluki and Whippet breeds. A proportional hazards (survival) model was developed in order to take sex, breed, age and geographical region into account in a multivariate analysis. Funding: Swedish University of Agricultural Sciences, The Foundation for Research.     

Characteristics of 234 dog bite incidents in Ireland during 2004 and 2005

Information was obtained by telephone interview from 100 dog owners whose dog had bitten a person, and from 134 victims of bites by a dog not owned by the victim. Three-quarters of the victims were female and aged from 21 to 60 years. The majority of the dogs were owned, male, two to six years old, over 10 kg in bodyweight and belonged to the popular breeds: collies, cocker/springer spaniels, terrier breeds, Jack Russell terriers, German shepherd dogs, golden retrievers and crossbreeds. The numbers of bites by the different breeds indicated that those that inflicted the most bites were the popular breeds rather than the breeds with any greater propensity to bite. Most attacks were rapid single bites and in 50 per cent of the cases, neither the owner nor the victim was able to identify any signal of the dog's intention to bite. Overall, 21 per cent of the incidents were rated as 'serious' and 2 per cent as 'life threatening'. One fifth of the dogs were euthanased as a result of the incident. Half the incidents required professional medical assistance for the victim. Almost half the incidents took place while the victim was walking or passing close to the dog's territory, or while the victim was interacting with the dog at home.     

Canine congenital portosystemic encephalopathy

The case records of 21 dogs with congenital portosystemic encephalopathy are reviewed. The disorder was most common in Australian cattledogs (blue heelers; 8 cases), Old English sheepdogs (3 cases) and Maltese terriers (3 cases). Extra-hepatic shunts occurred in small breeds, with the exception of 1 cattledog, while intra-hepatic shunts occurred in the medium to large breeds. The most common clinical pathology abnormalities were abnormal ammonia tolerance, mild to moderate increases in plasma alanine aminotransferase or alkaline phosphatase concentrations, decreased total serum protein concentrations, increased fasting ammonia concentrations and ammonium biurate crystalluria. Radiological examination revealed that all the dogs had a small liver. The kidneys were enlarged in 5 of 10 dogs in which kidney size could be estimated. Surgical ligation of an extra-hepatic shunt was successful in 2 of 4 dogs in which it was attempted. Medical management resulted in alleviation of clinical signs in 5 of 8 dogs. The period of successful treatment ranged from a few months to over a year.     

A cohort study of canine testicular neoplasia.

A prospective epidemiologic study of canine testicular neoplasia was undertaken in the Philadelphia area in 1971, with the cooperation of private veterinary practitioners. By the end of 1975, 938 dogs had been monitored for an average of 2 years. The cohort consisted of 609 cryptorchid and 329 age- and breed-matched controls. The incidence of testicular neoplasia in the cryptorchid subcohort was 12.7/1,000 dog-years at risk. Testicular neoplasms did not develop in controls. A large proportion of the dogs were below the average age at onset for this neoplasm. Among dogs over 6 years of age, the incidence was 68.1/1,000 dog-years at risk. The incidence of Sertoli cell tumors and seminoma was approximately twice as high in dogs with unilaterally retained inguinal testicles as in abdominal cryptorchids. Sertoli cell tumors developed in 10 dogs and seminoma developed in 6. One half of the testicular neoplasms that developed did so within the first year of observation. This study demonstrated the feasibility of conducting prospective epidemiologic studies of canine diseases with the assistance of practicing veterinarians.     

Breed, age and gender distribution of dogs with chronic hepatitis in the United Kingdom

Standardised histological criteria are now available for the diagnosis of canine chronic hepatitis (CH). CH is common in dogs, but no studies have reported breed, age and gender distributions in the United Kingdom (UK). The objective of this study was to determine which breeds had an increased risk for developing CH in the UK and to report the age and gender distribution for those breeds. The databases of six veterinary histopathology laboratories were searched for cases with a histological diagnosis of CH according to standardised criteria. The breed, age and gender of dogs was recorded and compared to a control population to calculate the odds ratio and 95% confidence intervals for developing CH. A total of 551 cases of CH were identified, consisting of 61 breeds. Nineteen breeds were represented by five or more cases. Breeds with an increased risk for developing CH included the American cocker spaniel, Cairn terrier, Dalmatian, Dobermann pinscher, English cocker spaniel, English springer spaniel, Great Dane, Labrador retriever and Samoyed. The median age at diagnosis for all breeds with CH was 8 years (range 7 months to 16 years). Dalmatians, Dobermann pinschers and English springer spaniels with CH were significantly younger than Cairn terriers, English cocker spaniels and Labrador retrievers with CH. Females were over-represented when all cases were examined together. In conclusion, several breeds in the UK have an increased risk of CH, some of which have not been previously reported.     

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

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 > or = 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 dog-years 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.