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

Gastric dilatation-volvulus in dogs

Gastric dilatation-volvulus (GDV) is a disease in which there is gross distension of the stomach with fluid or gas and gastric malpositioning. It causes pathology of multiple organ systems and is rapidly fatal. It is common in large- and giant-breed dogs. The disease appears to have a familial predisposition. Thoracic depth/width ratio also appears to predispose dogs to GDV. Implicated dietary factors include dietary particle size, frequency of feeding, speed of eating, aerophagia and an elevated feed bowl. A fearful temperament and stressful events may also predispose dogs to GDV. Abdominal distension, non-productive retching, restlessness, signs of shock, tachypnoea and dyspnoea are possible clinical signs. Initial treatment includes treatment of shock and gastric decompression. Surgical treatment should be performed promptly. There are no studies comparing the use of different anaesthetic agents in the anaesthetic management of GDV. Pre-medication with an opioid/benzodiazepine combination has been recommended. Induction agents that cause minimal cardiovascular changes such as opioids, neuroactive steroidal agents and etomidate are recommended. Anaesthesia should be maintained with an inhalational agent. Surgical therapy involves decompression, correction of gastric malpositioning, debridement of necrotic tissue, and gastropexy. Options for gastropexy include incisional, tube, circumcostal, belt-loop, incorporating, and laparoscopic gastropexy. Expected mortality with surgical therapy is 15-24%. Prognostic factors include mental status on presentation, presence of gastric necrosis, presence of cardiac arrhythmia and plasma lactate levels. Prophylactic gastropexy should be considered in dogs identified as being at high risk.

Benefits of prophylactic gastropexy for dogs at risk of gastric dilatation-volvulus

The lifetime probability of death from gastric dilation-volvulus (GDV) for five dog breeds was estimated based on published breed-specific longevity and GDV incidence. These breeds were Great Dane, Irish Setter, Rottweiler, Standard Poodle and Weimaraner. Lifetime risk (95% CI) of GDV in these breeds ranged from 3.9% (0-11.2%) for Rottweiler to 36.7% (25.2-44.6%) for Great Dane. A decision-tree analysis for prophylactic gastropexy--using lifetime probability of death from GDV and expected cost savings for veterinary services as outcome measures--was undertaken to determine the preferred course of action in several dog breeds. Prophylactic gastropexy was the preferred choice of action for all breeds examined, with the reduction in mortality (versus no gastropexy) ranging from 2.2-fold (Rottweiler) to 29.6-fold (Great Dane). Assuming a prophylactic gastropexy costs US$ 400, the procedure was cost-effective when the lifetime risk of GDV was > or = 34%. The maximum and minimum estimated breakeven costs for the gastopexy procedure ranged from US$ 20 (Rottweiler) to US$ 435 (Great Dane). The cost-effectiveness of prophylactic gastropexy was most sensitive to the cost of treating GDV (US$ 1500). Prophylactic gastropexy raises ethical issues that need to be considered by veterinarians and dog breeders.

Gastric dilatation-volvulus syndrome in dogs

Gastric dilatation-volvulus is a medical and surgical emergency that principally affects large-breed dogs. Surgical treatment should be undertaken as soon as the patient has been stabilized with fluid therapy and decompression. A gastrectomy might be required if the stomach is becoming necrotic. A gastropexy is required to prevent recurrence.

Bacteremia and bacterial translocation in the naturally occurring canine gastric dilatation-volvulus patient

This prospective study was performed to determine the prevalence of bacteremia in the naturally occurring gastric dilatation-volvulus (GDV) patient, the possible relationship between bacteremia and survival, and whether bacteremia was a result of translocation from the stomach. Blood cultures were collected from each patient. Bacterial cultures were collected from the liver, mesenteric lymph node, and stomach. Forty-three percent of the GDV cases and 40% of the controls developed positive blood cultures. Gram-negative rods were the most frequently isolated organisms. Evidence of bacterial translocation from the stomach could not be demonstrated in GDV patients, and survival was not affected by the presence of bacteremia.

Triage and approach to the acute abdomen

The presentation of a patient with acute abdominal pain often is both a diagnostic and therapeutic challenge for the veterinary practitioner. Rapid physical examination and assessment of the patient's cardiovascular status are critical to initiating appropriate and often aggressive medical management as diagnostic tests are being performed. A number of diagnostic tests can be performed, including complete blood count, serum biochemistry profile, serum amylase and lipase, abdominal radiographs, abdominal ultrasound, abdominal paracentesis or diagnostic peritoneal lavage, cytology, and fluid analysis. In some cases, surgical exploration may be indicated, depending on each patient's clinical signs and response to therapy. Of the most important aspects of medical management of the patient with acute abdominal pain is to maintain oxygen delivery to tissues and to treat aggressively for pain or discomfort. The initial triage and approach to the patient with acute abdomen are discussed.

Prospective evaluation of laparoscopic-assisted gastropexy in dogs susceptible to gastric dilatation

OBJECTIVE

To determine long-term outcome associated with laparoscopic-assisted gastropexy in prevention of gastric dilatation-volvulus (GDV) in susceptible dogs and to evaluate use of laparoscopy to correct GDV.

DESIGN

Prospective study.

ANIMALS

25 client-owned large-breed dogs.

PROCEDURE

23 dogs susceptible to GDV were referred as candidates for elective gastropexy. These dogs had a history of treatment for gastric dilatation, clinical signs of gastric dilatation, or family members with gastric dilatation. Laparoscopic-assisted gastropexy was performed. One year after surgery, abdominal ultrasonography was performed to evaluate the attachment of the stomach to the abdominal wall. Two dogs with GDV were also treated with laparoscopic-assisted derotation of the stomach and gastropexy.

RESULTS

None of the dogs developed GDV during the year after gastropexy, and all 20 dogs examined ultrasonographically had an intact attachment. Another dog was euthanatized at 11.5 months for unrelated problems. Two dogs with GDV successfully underwent laparoscopic-assisted gastropexy after the stomach was repositioned.

CONCLUSIONS AND CLINICAL RELEVANCE

Laparoscopic-assisted gastropexy resulted in a persisting attachment between the stomach and abdominal wall, an absence of GDV development, and few complications. Dogs with a high probability for development of GDV should be considered candidates for minimally invasive gastropexy. Carefully selected dogs with GDV can be treated laparoscopically.

Relationship between incidence of gastric dilatation-volvulus and biometeorologic events in a population of military working dogs

OBJECTIVE

To calculate the monthly incidence of gastric dilatation-volvulus (GDV) in a population of military working dogs during a 5-year period and determine whether there was an association with synoptic climatologic indices.

SAMPLE POPULATION

Medical records of all military working dogs housed at Lackland Air Force Base,Tex, from Jan 1, 1993 to Dec 31, 1997.

PROCEDURE

Confirmed cases of GDV were identified from evaluation of medical records and used to calculate incidence of GDV. Factor analysis of local climatologic data was used to classify each day into 1 of 8 meteorologically homogeneous types of days for this location. Occurrence of GDV was compared with frequency of occurrence of synoptic climatologic days.

RESULTS

48 cases of GDV were identified from January 1993 through December 1997 Mean monthly incidence was 2.5 cases/1,000 dogs at risk (range, 0 to 18.5 cases/1,000 dogs; median, 2.5 cases/1,000 dogs). A seasonal increase in incidence of GDV was detected, because half of the episodes were during November, December, and January. An association with a specific synoptic climatologic day was not detected.

CONCLUSIONS AND CLINICAL RELEVANCE

Seasonal fluctuations in incidence of GDV may be associated with external factors that precipitate physiologic changes resulting in GDV. Although a specific cause-effect relationship was not documented, clinicians must be alert for the potential of seasonal variation in incidence of GDV and accordingly heighten their index of suspicion for the condition, particularly in populations of dogs that are predisposed to development of GDV.

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.