Mortality and morbidity due to gastric dilatation-volvulus syndrome in pedigree dogs in the UK

Learning Curve in Two-Port Laparoscopic Gastropexy Using FlexDex

OBJECTIVES

Keyhole gastropexy is becoming increasingly popular, and the new development facilitates shorter surgical times. This paper reports on the learning curve in two-port laparoscopic gastropexy using FlexDex in a specialist's hands. FlexDex is a novel tool combining aspects of robotic surgery without requiring an expensive robot theatre setting.

METHODS

Cohort of 16 dogs >25 kg and at high risk of gastric volvulus and dilatation (GDV) undergoing elective laparoscopic gastropexy were enrolled in the study consecutively from 5/2022 to 9/2023. All patients were operated on by one surgeon (FM), and surgical time was recorded to assess learning curve. Competence was defined as plateauing surgical time. Detailed follow-up at 1 day, 7 days, 14 days, 2 months, 6 months, and long-term was recorded for success rate and complications. Ultrasound examination was scheduled at 4-6-month review to confirm lasting success of the gastropexy.

RESULTS

All 16 patients were operated on successfully without any significant complications, as confirmed on the ultrasound. The surgical time of laparoscopic gastropexy reduced from 52 to 14 min (reduction of 38 min/73%) and reached plateau after the 12th case of the 16, making it a very steep learning curve in specialist hands. There were no serious complications, and success rate was 100% at the 6-month ultrasound assessment.

CLINICAL SIGNIFICANCE

This is the first paper to report on the learning curve with the FlexDex device in a two-port laparoscopic gastropexy setting. It effectively halves the operating time to 30 min, making the surgery safer for the patient and more cost-efficient, without compromising the result.

Mastiff breed mortality: A study of owner experience, dog age and longevity

•

Mastiffs are a group of large and giant powerful dogs consisting of 19 breeds worldwide.

•

The median age of death for the Mastiff group was 8 years with European and North American dogs also dying at this age.

•

A higher percentage of dogs died over 8 years when classed as senior within breed standards.

•

Cancer was the most common cause of death in the Mastiff group with osteosarcoma the most common specifically in neutered animals.

Despite being ranked 33 in Americas most popular breeds (American Kennel Club, 2020), there is a lack of research addressing longevity and death related health problems of Mastiff dog breeds and specifically commonly kept Bull Mastiffs and English Mastiffs. Likely a result of small founder populations and minimal breeding geographical locations, limited genetic variation is found making it important to determine key health concerns which may reduce longevity. The purpose of this study was to report findings from an online global survey of owners of deceased Mastiffs detailing breed, age at death, and if known, cause of death. Owner information was also collected including location by continent and country and the owners breeding or hobbyist experience. A closed-question survey was used via an online network of global Mastiff clubs and associations totalling a useable sample of 1036 dogs across a range of breeds. Notably, it is reported that age and cause of death varied dependant on breed. Results indicate that the median age of death for all dogs was 8 years with mean age of death in Europe as 7.72 years and 8.17 years in North America. The most common cause of death identified for all dogs was cancer (47%), old age (16%), cardiac problems (8%) and gastric problems including GDV and bloat (7%). The mean age of death for cancer dogs was 7.85 years with 23 types of cancer stated with Osteosarcoma being the most commonly recorded and specifically for neutered animals. As the survey was aimed at hobbyist and registered breeders, study findings contribute to knowledge of Mastiff mortality with the aim of promoting welfare of the breed.

Retrospective analysis of 736 cases of canine gastric dilatation volvulus

OBJECTIVE

To identify factors influencing the survival of confirmed gastric dilatation volvulus (GDV) cases presented to a specialist referral and emergency hospital.

METHODS

Clinical records of confirmed GDV cases admitted to two specialist referral and emergency centres in Sydney (Animal Referral Hospital (ARH) Homebush and ARH Baulkham Hills) between July 1999 and July 2019 were searched.

RESULTS

A total of 736 GDV cases were reviewed, of which 460 dogs were surgically treated and 276 dogs were humanely killed. The survival rates of patients operated on by general surgeons and specialists were 81.7% and 88.7%, respectively. Both incisional gastropexy and belt-loop gastropexy were clinically effective in treating GDV, with no significant difference in survival rates. Intraoperative mortality rates for general surgeons and specialists were 7.0% and 2.9%, respectively. The odds of mortality in dogs operated on by general surgeons were 2.03 times those operated on by specialist surgeons. The odds of mortality in dogs presented between 3:00 and 9:00 am were 3.57 times those of dogs presented between 9:00 am and 9:00 pm. The odds of mortality in dogs where the duration from presentation to completion of surgery was more than 3 h were 2.53 times those of dogs where time lapsed was equal or less than 3 h.

CONCLUSION

The results suggested that admission time was statistically significantly related to the survival rate. Dogs operated on by specialist surgeons had a significantly higher survival rate compared to those operated on by general surgeons. Clinicians should aim to stabilise and complete surgical correction of GDV as soon as possible to decrease the mortality.

Acid-Base, Electrolyte and Lactate Abnormalities as Well as Gastric Necrosis and Survival in Dogs With Gastric Dilation-Volvulus Syndrome. A Retrospective Study in 75 Dogs

Gastric dilation-volvulus (GDV) syndrome in dogs is associated with complex metabolic, acid-base, and electrolyte abnormalities. The aim of this study was to evaluate previously analyzed factors (lactate and BE) in combination with other acid-base parameters (pH, pCO₂, bicarbonate, base excess [BE], anion gap [AG], and strong ion difference) and electrolyte concentrations and to evaluate their association with the incidence of gastric necrosis and outcome in dogs with GDV. A retrospective study in 75 dogs with gastric dilation-volvulus syndrome, University veterinary teaching hospital. Medical records were reviewed including signalment, history, initial plasma lactate, acid-base parameters, and electrolyte concentrations, surgical findings and outcome. The overall mortality was 18.7%. In dogs with gastric necrosis, higher initial plasma lactate (median 5.84 vs. 3.36 mmol/L) and AG (20.7 vs. 16.55 mmol/L) and lower pH (7.29 vs. 7.36), bicarbonate (18.7 vs. 22.9 mmol/L), and BE concentration (-8.1 vs. -1.85 mmol/L) were found compared to dogs without gastric necrosis. Anorganic phosphorus was the only electrolyte investigated for which a significant difference was noted between dogs with and without gastric necrosis (1.93 vs. 1.39 mmol/L). The initial plasma lactate concentration (3.36 mmol/L vs. 9.68 mmol/L) and AG (16.8 vs. 20.95 mmol/L) were lower in survivors than nonsurvivors. Survivors had higher pH (7.35 vs. 7.27), bicarbonate concentrations (22.9 vs. 17.35 mmol/L), and BE (-1.9 vs. -9.55 mmol/L) compared to nonsurvivors. Anorganic phosphorus was ultimately the only electrolyte with a significant difference between survivors and nonsurvivors (1.4 vs. 1.84 mmol/L). A multivariate logistic regression model of combination lactate, pH, bicarbonate, BE, AG, and anorganic phosphorus identified pH ≤7.331 and bicarbonate as factors independently associated with gastric necrosis. Similarly, pH ˃7.331, bicarbonate and anorganic phosphorus were independently associated with outcome. Higher initial plasma lactate, AG and anorganic phosphorus levels, and lower pH, BE and bicarbonate concentrations were found in GDV dogs with gastric necrosis. Similarly, initially higher plasma lactate, AG and anorganic phosphorus concentrations, and lower pH, BE and bicarbonate were found in GDV dogs who required euthanasia or who died after surgery. Of these parameters, pH and bicarbonate were strongly and independently associated with gastric necrosis, and pH, bicarbonate and phosphorus were independently associated with outcome.

Evaluation of gastric motility in nine dogs before and after prophylactic laparoscopic gastropexy: a pilot study

BACKGROUND

The purpose of this study was to evaluate the effect of a prophylactic laparoscopic gastropexy on gastric motility in healthy large-breed dogs.

METHODS

This was a prospective pilot study with nine healthy client-owned dogs. Each dog was its own control. Gastric motility was evaluated before and after laparoscopic gastropexy. Dogs were fed a standard diet three weeks before and after surgery. Gastric motility was measured before and 3 weeks after surgery. A wireless motility capsule (WMC) was used to measure gastric pH, intragastric pressure, temperature, frequency of contractions, motility index (MI) and transit time. Non-parametric statistical analysis was used to compare the paired data. Clients were contacted for follow-up information 2 years postoperatively.

RESULTS

Median frequency of gastric contractions was 1.3 (range, 0.6-1.9 contractions/min) before gastropexy and 1.0 (range, 0.3-2.6 contractions/min) after gastropexy (P = 0.820). Median MI was 49.2 (range, 23.7-96.6) before gastropexy and 28.1 (range, 12.2-148.9) after gastropexy (P = 0.652). Median gastric emptying time was 1140 (range, 486-1230 min) before gastropexy and 1110 (range, 306-2610 min) after gastropexy (P = 0.570). During the hour before the WMC passed through the pylorus, median MI was 72.2 (range, 48.2-549.3) before gastropexy and 52.9 (range, 15.20-322.8) after gastropexy (P = 0.734), and frequency of contractions was 1.1 (range, 0.9-4.1 contractions/min) before gastropexy and 1.2 (range, 0.5-3.0 contractions/min) after gastropexy (P = 0.652).

CONCLUSION

Motility in the stomach did not change in healthy dogs after prophylactic laparoscopic gastropexy. We conclude that preventive laparoscopic gastropexy does not induce gastroparesis.

Risk Factors Associated with Lifespan in Pet Dogs Evaluated in Primary Care Veterinary Hospitals

The objective of this population-based retrospective cohort study was to identify factors associated with lifespan in pet dogs evaluated at primary care veterinary hospitals. Dogs ≥3 mo of age that visited any of 787 US hospitals at least twice from January 1, 2010, through December 31, 2012, were included. Survival curves were constructed for dogs by reproductive status, breed, body size, and purebreed (versus mixed-breed) status. Multivariate Cox proportional hazard regression was performed to identify factors associated with lifespan. There were 2,370,078 dogs included in the study, of whom 179,466 (7.6%) died during the study period. Mixed-breed dogs lived significantly longer than purebred dogs, and this difference was more pronounced as body size increased. Controlling for other factors, dogs of either sex had a greater hazard of death over the study follow-up period if sexually intact rather than gonadectomized. For dogs who lived to 2 yr of age, the hazard of death decreased with increasing frequency of dental scaling. Our findings support previous reports of the impact of body size and gonadectomy on lifespan and provide new evidence in support of ultrasonic dental scaling and mixed breeding.

Diagnosis of chronic gastric instability using computed tomography in a Great Dane that progressed to gastric dilatation and volvulus: a literature review and case report

Chronic gastric instability (CGI) is part of the gastric dilatation and volvulus (GDV) complex and contributes to the pathophysiologic mechanism of volvulus. Clinical signs can be attributed to a flaccid and mobile stomach. This manuscript reviews the literature regarding CGI and presents a case where computerized tomography is utilized in combination with abdominal radiography to diagnose CGI in an 8 year old spayed female Great Dane. The patient presented for nonspecific clinical signs including hypersalivation, anorexia, and regurgitation, and was euthanized after failing medical management and developing acute abdominal pain. Necropsy revealed a distended stomach with 180^o rotation along its long axis. This case demonstrates that CGI and GDV share a continuum, and cases of CGI may progress to GDV without prophylactic surgical intervention.

The canine gut microbiome is associated with higher risk of gastric dilatation-volvulus and high risk genetic variants of the immune system

BACKGROUND

Large and giant dog breeds have a high risk for gastric dilatation-volvulus (GDV) which is an acute, life-threatening condition. Previous work by our group identified a strong risk of GDV linked to specific alleles in innate and adaptive immune genes. We hypothesize that variation in the genes of the immune system act through modulation of the gut microbiome, or through autoimmune mechanisms, or both, to predispose dogs to this condition. Here, we investigate whether differences in the canine fecal microbiome are associated with GDV and are linked to previously identified risk alleles.

METHODOLOGY/PRINCIPLE FINDINGS

Fecal samples from healthy Great Danes (n = 38), and dogs with at least one occurrence of GDV (n = 37) were collected and analyzed by paired-end sequencing of the 16S rRNA gene. Dietary intake and temperament were estimated from a study-specific dietary and temperament questionnaire. Dogs with GDV had significantly more diverse fecal microbiomes than healthy control dogs. Alpha diversity was significantly increased in dogs with GDV, as well as dogs with at least one risk allele for DRB1 and TRL5. We found no significant association of dietary intake and GDV. Dogs with GDV showed a significant expansion of the rare lineage Actinobacteria (p = 0.004), as well as a significantly greater abundance of Firmicutes (p = 0.004) and a significantly lower abundance of Bacteroidetes (p<0.004). There was a significant difference in the abundance of 10 genera but after correction for multiple comparisons, none were significant. Bacterial phyla were significantly different between controls and dogs with GDV and at least one risk allele for DRB1 and TRL5. Actinobacteria were significantly higher in dogs with GDV and with one risk allele for DRB1 and TLR5 but not DLA88 genes. Furthermore, Collinsella was significantly increased in dogs with at least one risk allele for DRB1 and TLR5. Logistic regression showed that a model which included Actinobacteria, at least one risk allele,and temperament, explained 29% of the variation in risk of GDV in Great Danes.

CONCLUSIONS

The microbiome in GDV was altered by an expansion of a minor lineage and was associated with specific alleles of both innate and adaptive immunity genes. These associations are consistent with our hypothesis that immune genes may play a role in predisposition to GDV by altering the gut microbiome. Further research will be required to directly test the causal relationships of immune genes, the gut microbiome and GDV.

Associations between gastric dilatation-volvulus in Great Danes and specific alleles of the canine immune-system genes DLA88, DRB1, and TLR5

OBJECTIVE To determine whether specific alleles of candidate genes of the major histocompatibility complex (MHC) and innate immune system were associated with gastric dilatation-volvulus (GDV) in Great Danes. ANIMALS 42 healthy Great Danes (control group) and 39 Great Danes with ≥ 1 GDV episode. PROCEDURES Variable regions of the 2 most polymorphic MHC genes (DLA88 and DRB1) were amplified and sequenced from the dogs in each group. Similarly, regions of 3 genes associated with the innate immune system (TLR5, NOD2, and ATG16L1), which have been linked to inflammatory bowel disease, were amplified and sequenced. Alleles were evaluated for associations with GDV, controlling for age and dog family. RESULTS Specific alleles of genes DLA88, DRB1, and TLR5 were significantly associated with GDV. One allele of each gene had an OR > 2 in the unadjusted univariate analyses and retained a hazard ratio > 2 after controlling for temperament, age, and familial association in the multivariate analysis. CONCLUSIONS AND CLINICAL RELEVANCE The 3 GDV-associated alleles identified in this study may serve as diagnostic markers for identification of Great Danes at risk for GDV. Additional research is needed to determine whether other dog breeds have the same genetic associations. These findings also provided a new target for research into the etiology of, and potential treatments for, GDV in dogs.

Gastric dilation-volvulus in dogs attending UK emergency-care veterinary practices: prevalence, risk factors and survival

OBJECTIVE

To report prevalence, risk factors and clinical outcomes for presumptive gastric dilation-volvulus diagnosed among an emergency-care population of UK dogs.

METHODS

The study used a cross-sectional design using emergency-care veterinary clinical records from the VetCompass Programme spanning September 1, 2012 to February 28, 2014 and risk factor analysis using multivariable logistic regression modelling.

RESULTS

The study population comprised 77,088 dogs attending 50 Vets Now clinics. Overall, 492 dogs had presumptive gastric dilation-volvulus diagnoses, giving a prevalence of 0·64% (95% Confidence interval: 0·58 to 0·70%). Compared with cross-bred dogs, breeds with the highest odds ratios for the diagnosis of presumptive gastric dilation-volvulus were the great Dane (odds ratio: 114·3, 95% Confidence interval 55·1 to 237·1, P<0·001), akita (odds ratio: 84·4, 95% Confidence interval 33·6 to 211·9, P<0·001) and dogue de Bordeaux (odds ratio: 82·9, 95% Confidence interval 39·0 to 176·3, P<0·001). Odds increased as dogs aged up to 12 years and neutered male dogs had 1·3 (95% Confidence interval 1·0 to 1·8, P=0·041) times the odds compared with entire females. Of the cases that were presented alive, 49·7% survived to discharge overall, but 79·3% of surgical cases survived to discharge.

CLINICAL SIGNIFICANCE

Approximately 80% of surgically managed cases survived to discharge. Certain large breeds were highly predisposed.

Multiple Genetic Associations with Irish Wolfhound Dilated Cardiomyopathy

Cardiac disease is a leading cause of morbidity and mortality in dogs and humans, with dilated cardiomyopathy being a large contributor to this. The Irish Wolfhound (IWH) is one of the most commonly affected breeds and one of the few breeds with genetic loci associated with the disease. Mutations in more than 50 genes are associated with human dilated cardiomyopathy (DCM), yet very few are also associated with canine DCM. Furthermore, none of the identified canine loci explain many cases of the disease and previous work has indicated that genotypes at multiple loci may act together to influence disease development. In this study, loci previously associated with DCM in IWH were tested for associations in a new cohort both individually and in combination. We have identified loci significantly associated with the disease individually, but no genotypes individually or in pairs conferred a significantly greater risk of developing DCM than the population risk. However combining three loci together did result in the identification of a genotype which conferred a greater risk of disease than the overall population risk. This study suggests multiple rather than individual genetic factors, cooperating to influence DCM risk in IWH.

Pyloric localisation in 57 dogs of breeds susceptible to gastric dilatation-volvulus in the UK using computed tomography

OBJECTIVE

Describe the location of the pylorus using CT in dog breeds susceptible to gastric dilatation-volvulus in the UK.

METHODS

Descriptive anatomical study. Abdominal CT scans of 57 client-owned dogs were reviewed to assess pyloric position relative to the 9th, 10th, 11th and 13th ribs and 2 and 3 cm caudal to the 13th rib at the 8, 9 and 10 o'clock positions. The angle of the pylorus from the centre of the abdominal cavity relative to the sagittal plane was also determined.

RESULTS

In 88 per cent of cases, the pylorus was located in the right cranioventral abdomen with 63 per cent positioned at the 9-10 o'clock position. The overall distance between the pylorus and right abdominal wall (RAW) at the 13th rib 10 o'clock position was equivalent to 29 per cent of ventral abdominal length, significantly greater than the median overall distance of ∼14 per cent of ventral abdominal length between the pylorus and RAW at the 9th or 10th rib 10 o'clock position (P<0.0001).

CLINICAL SIGNIFICANCE

Common gastropexy locations may result in considerable displacement of the pylorus relative to its natural anatomic location. Further case-control studies are required to assess the clinical significance of this finding.

A retrospective study of gastric dilatation and gastric dilatation and volvulus in working farm dogs in New Zealand

AIMS

To present findings from a case series of gastric dilatation (GD) or gastric dilatation and volvulus (GDV) in working farm dogs in New Zealand that were examined at veterinary clinics, and to identify possible risk factors for GD or GDV in working farm dogs in New Zealand using a case-control study.

METHODS

This retrospective study included a case-series and a case-control study. The case series analysed information from 62 case records of GD or GDV in working farm dogs seen between August 2004 and September 2009 at 13 veterinary clinics throughout New Zealand. Cases were classified as GD or GDV if the diagnosis was confirmed by radiography, surgery or post-mortem examination. Details of history and treatment, as well as outcomes, were obtained for each case. For the case-control study, records of 41 working farm dogs with GD or GDV (cases) seen between April 2008 and April 2009, and 82 working farm dogs examined because of trauma over the same period and in the same 13 clinics (controls), were used to model the risk factors for GD or GDV.

RESULTS

From the case-series study, 40/62 (65%) cases of GD or GDV that were examined and treated at the veterinary clinics returned to work. Of the 41 dogs where the gastric contents were recorded, 25 (61%) had predominantly food or bones in the stomach, and 26/27 dogs had a history of having eaten meat, bones or scavenged a carcass. The case-control study showed that the significant risk factors for GD or GDV, compared with control dogs presenting with trauma, were breed, age and season. The odds that a case of GD or GDV was a Huntaway, after adjusting for age and season, was 19 times higher than the odds a control was a Huntaway. Gender and bodyweight were not identified as risk factors.

CONCLUSIONS AND CLINICAL RELEVANCE

A high proportion of farm working dogs with GD or GDV were successfully treated by veterinarians. The risk of a case of GD or GDV being a Huntaway was significantly higher than for a dog presenting as a trauma case. However the influences of the season of the year, climatic factors and nutritional factors on the pathogenesis need to be identified before adequate preventative measures can be recommended.

Chronic gastric instability and presumed incomplete volvulus in dogs

Chronic gastric volvulus in dogs results in long-standing gastrointestinal signs unlike those of acute gastric dilatation and volvulus. This report describes chronic gastric volvulus in seven dogs. The majority of dogs presented with weight loss, chronic vomiting, lethargy and abdominal pain. A combination of radiographic, ultrasonographic and endoscopic imaging indicated altered positioning of gastric landmarks. Dynamic changes were identified in some cases. Exploratory coeliotomy and surgical gastropexy were performed in all dogs. Clinical signs improved or resolved in six of seven dogs postoperatively. Chronic gastric volvulus is an uncommon condition in dogs, but should be considered as a differential in cases presenting with the above clinical signs.