Meteorological influence on the occurrence of gastric dilatation-volvulus in military working dogs in Texas

Retrospective evaluation of factors associated with emergency frequency and survival in equids presenting for emergency care (2019-2020): 3071 cases

OBJECTIVE

To determine factors associated with frequency and outcome of equid emergencies in private practice.

DESIGN

Retrospective study from February 2019 to January 2020.

SETTING

Private practice large animal hospital.

ANIMALS

A total of 3071 equids of various breeds and ages presenting for emergency care.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Variables included for analysis of daily emergency frequency included day of the week, month, and daily climate data. A Poisson regression model found the maximum temperature (P = 0.05), average barometric pressure (P = 0.005), and decreases in barometric pressure (P = 0.05) were associated with an increasing daily number of emergencies. Overall survival for all emergencies was 89% (2748/3071). Variables included for analysis of nonsurvival for emergencies included signalment, body system, clinical examination findings, laboratory data, and experience of the veterinarian. A logistic regression model for primary emergencies (nonreferral) found that increasing age, increasing heart rate, and decreased gastrointestinal sounds were associated with an increase in nonsurvival. Body system and experience of the veterinarian affected nonsurvival. A logistic regression model for all emergencies (primary and referral) found that absent gastrointestinal sounds and an increasing PCV were associated with increased nonsurvival.

CONCLUSIONS

The number of daily emergencies in this practice was affected by the month of the year and day of the week. Additionally, hotter days, increased barometric pressure, or drops in barometric pressure are likely to be associated with a higher emergency caseload. Nonsurvival of primary equid emergencies in private practice increases with age, higher heart rates, and decreased gastrointestinal sounds.

Lack of Association Between Barometric Pressure and Incidence of Colic in Equine Academic Ambulatory Practice

Anecdotal accounts correlate equine colic onset to changing weather conditions; however, atmospheric effects on colic have not been studied extensively. We hypothesized that changes in barometric pressure would increase the likelihood of a colic diagnosis compared with other noncolic sick events. Multivariable logistic regression analysis was used to look for associations between colic diagnosis and barometric pressure. The University of Pennsylvania Field Service electronic medical records were searched by identifiable examination type via billing procedure codes collecting 3,108 emergent and nonemergent medical events along with corresponding weather data from the National Weather Service from January 1, 2005, through January 1, 2017. Barometric pressure values and changes were not found to be statistically associated with a diagnosis of colic (P = .1). Horses that did not survive were almost 12 times more likely to have a diagnosis of colic (odds ratio [OR]: 11.97; P < .0001). Horses with disease recurrence were 30% more likely to have a diagnosis of colic (OR: 1.29; P = .006). The likelihood of colic diagnosis increased with increasing latitude (OR: 2.43; P = .04). Horses were more likely to be diagnosed with colic in the fall (OR: 1.72; P < .0001), spring (OR: 1.29; P = .04), and summer (OR: 1.85; P < .0001), compared with winter. Stallions were 48% less likely to colic compared with mares (OR: 0.52; P = .016) and Quarter Horses were 32% less likely to colic compared with Thoroughbreds and Arabians (OR: 0.68; P = .047). This study provided evidence that changes in barometric pressure were not a contributing risk factor for colic, although seasons with changing weather and latitude may play a role.

Investigation of potential risk factors for mesenteric volvulus in military working dogs

OBJECTIVE To identify risk factors for mesenteric volvulus (MV) in military working dogs (MWDs). DESIGN Retrospective case-control study. ANIMALS 211 MWDs (54 with and 157 without MV [case and control dogs, respectively]). PROCEDURES Medical records (cases and controls) and necropsy reports (cases) were reviewed. Signalment, pertinent medical and surgical history, behavior and temperament characteristics, feeding schedules, and training types were recorded. Weather patterns for regions where dogs resided were researched. Data were evaluated statistically to identify potential risk factors for MV. RESULTS Risk factors significantly associated with MV included German Shepherd Dog breed (OR, 11.5), increasing age (OR, 2.0), and history of prophylactic gastropexy (OR, 65.9), other abdominal surgery (after gastropexy and requiring a separate anesthetic episode; OR, 16.9), and gastrointestinal disease (OR, 5.4). Post hoc analysis of the subset of MWDs that underwent gastropexy suggested that postoperative complications were associated with MV in these dogs but type of gastropexy and surgeon experience level were not. CONCLUSIONS AND CLINICAL RELEVANCE Data supported earlier findings that German Shepherd Dog breed and history of gastrointestinal disease were risk factors for MV. The MWDs with a history of prophylactic gastropexy or other abdominal surgery were more likely to acquire MV than were those without such history. These findings warrant further study. Despite the association between prophylactic gastropexy and MV, the authors remain supportive of this procedure to help prevent the more common disease of gastric dilatation-volvulus.

An Internet-based survey of risk factors for surgical gastric dilatation-volvulus in dogs

OBJECTIVE

To evaluate risk factors for gastric dilatation-volvulus (GDV) in a large number of privately owned dogs across a wide geographic area.

DESIGN

Internet-based, cross-sectional study.

ANIMALS

2,551 privately owned dogs.

PROCEDURES

A questionnaire addressed dog-specific, management, environmental, and personality-associated risk factors for GDV in dogs. Respondents were recruited through the posting of the electronic link to the questionnaire on websites for dog owners; the information was also disseminated at meetings of dog owners and via newsletters, e-mail lists for dog owners and breeders, owner-oriented dog publications, and e-mails forwarded by participants. Descriptive statistics and logistic regression analysis were performed.

RESULTS

Factors significantly associated with an increased risk of GDV were being fed dry kibble, anxiety, residence in the United Kingdom, being born in the 1990s, being a family pet, and spending at least 5 hours a day with the owner. Factors associated with a decreased risk of GDV were playing with other dogs and running the fence after meals, fish and egg dietary supplements, and spending equal time indoors and outdoors. A significant interaction between sex and neuter status was observed, with sexually intact females having the highest risk for GDV.

CONCLUSIONS AND CLINICAL RELEVANCE

In dogs with a high risk of GDV, regular moderate daily and postprandial activity appeared to be beneficial. Feeding only commercial dry dog food may not be the best choice for dogs at risk; however, supplements with fish or eggs may reduced this risk. The effect of neuter status on GDV risk requires further characterization.

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.

A time series model of the occurrence of gastric dilatation-volvulus in a population of dogs

Background

Gastric dilatation-volvulus (GDV) is a life-threatening condition of mammals, with increased risk in large breed dogs. The study of its etiological factors is difficult due to the variety of possible living conditions. The association between meteorological events and the occurrence of GDV has been postulated but remains unclear. This study introduces the binary time series approach to the investigation of the possible meteorological risk factors for GDV. The data collected in a population of high-risk working dogs in Texas was used.

Results

Minimum and maximum daily atmospheric pressure on the day of GDV event and the maximum daily atmospheric pressure on the day before the GDV event were positively associated with the probability of GDV. All of the odds/multiplicative factors of a day being GDV day were interpreted conditionally on the past GDV occurrences. There was minimal difference between the binary and Poisson general linear models.

Conclusion

Time series modeling provided a novel method for evaluating the association between meteorological variables and GDV in a large population of dogs. Appropriate application of this method was enhanced by a common environment for the dogs and availability of meteorological data. The potential interaction between weather changes and patient risk factors for GDV deserves further investigation.